CLINICAL REPORT
Variable Expressivity of Pfeiffer Syndrome in a Family With FGFR1 p.Pro252Arg Mutation Bea´ta Bessenyei,1* Mariann Tihanyi,2 Marianna Hartwig,2 Katalin Szakszon,3 and ´Eva Ola´h3 1
Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
2
Genetic Laboratory, Hospital of Zala County, Zalaegerszeg, Hungary
3
Department of Pediatrics, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
Manuscript Received: 26 March 2014; Manuscript Accepted: 20 August 2014
Pfeiffer syndrome is an autosomal dominant disorder classically characterized by craniosynostosis, facial dysmorphism and limb anomalies. The majority of cases are caused by mutations in the fibroblast growth factor receptor 2 (FGFR2) gene. A specific, rare mutation p.Pro252Arg, located between the second and third extracellular immunoglobulin-like domain of FGFR1, is associated with mild clinical signs. We report on a three-generation family with five members having a heterozygous FGFR1 p. Pro252Arg mutation. Phenotypic features within the family showed high variability from the apparently normal skull and limbs to the characteristic brachycephaly and digital anomalies. The typical features of Pfeiffer syndrome appeared only in the third generation allowing us to unveil the syndrome in several further family members in two previous generations. Variable expressivity can complicate the recognition of Pfeiffer syndrome, principally the mild type 1, requiring careful phenotyping and genetic counseling. Ó 2014 Wiley Periodicals, Inc.
Key words: Pfeiffer syndrome; craniosynostosis; FGFR1; syndactyly; clinodactyly
How to Cite this Article: Bessenyei B, Tihanyi M, Hartwig M, Szakszon K, Ola´h E´. 2014. Variable expressivity of pfeiffer syndrome in a family with FGFR1 p.Pro252Arg mutation. Am J Med Genet Part A 164A:3176–3179.
et al., 1995]. FGFR2 mutations occuring in all types of PS are frequently detected in exons IIIa and IIIc and they are found in the great majority of PS cases. A specific mutation, p.Pro252Arg of FGFR1, is quite rare in this syndrome and associates with type 1 PS. Patients with this mutation usually have very mild craniofacial features with variable presence of craniosynostosis [Rossi et al., 2003; Hackett and Rowe, 2006]. Hereby we report a threegeneration family with PS type 1 associated with the specific FGFR1 p.Pro252Arg mutation. The mutation was detected in five members of the family. The phenotype proved to be highly variable, from the apparently normal skull to the obvious brachycephaly and dysmorphic features. Abnormalities of the digits especially on the feet were consistently present in all family members affected by the mutation.
INTRODUCTION Pfeiffer syndrome (PS) is an autosomal dominantly inherited craniosynostosis disorder affecting about 1 in 100,000 individuals. It is clinically and genetically heterogeneous with variable clinical severity [Robin et al., 1998; Teebi et al., 2002; Lajeunie et al., 2006]. Typical symptoms include abnormal skull shape, facial dysmorphism and limb anomalies. The characteristic cranial features are brachycephaly due to craniosynostosis, high forehead, midface hypoplasia, convex nasal ridge, depressed nasal bridge, hypertelorism and ocular proptosis [Pfeiffer, 1964]. Patients have broad thumbs and big toes usually deviated from the other digits. Syndactyly of the second and third fingers and toes is also common [Rossi et al., 2003]. Pfeiffer syndrome patients may manifest additional abnormalities including neurological, visual, auditory, and visceral problems. Based on the severity of the phenotype, PS can be divided into three clinical subtypes of diagnostic and prognostic significance [Cohen, 1993]. Pfeiffer syndrome is caused by activating mutations in the fibroblast growth factor receptor (FGFR) 1 and 2 genes [Schell
Ó 2014 Wiley Periodicals, Inc.
CLINICAL REPORT The index patient, a female newborn was referred to the genetic counseling of the Hospital of Zala County, Hungary. She was the first child of no-consanguineous Caucasian parents. The father was 33, the mother was 26 years old at the time of conception. The mother had one healthy child from her previous relationship. During Conflict of interest disclosure: The authors have no conflict of interest and disclose any financial interest. Correspondence to: Bea´ta Bessenyei, Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary 98. Nagyerdei krt., Debrecen H-4032. E-mail: [email protected] Article first published online in Wiley Online Library (wileyonlinelibrary.com): 23 September 2014 DOI 10.1002/ajmg.a.36774
3176
BESSENYEI ET AL. pregnancy, the mother received fraxiparine treatment due to muscle treat, and was operated on to correct aortic insufficiency. The index patient was delivered spontaneously at term with a birth weight of 3,200 g (50th centile), length 48 cm (10–25th centile) and occipitofrontal circumference 32 cm (10–25th centile). Her abnormal skull configuration and facial dysmorphism were noted already at birth: she had brachy- and acrocephaly, high forehead, wide and depressed nasal bridge, hypertelorism, flat bulbous nose-tip with a broad nasal base and thick alae nasi, anteverted nares, long philtrum, thin lip vermilion, horizontal groove under the lower lip, low-set ears with overfolded helices (Fig. 1A). Limb anomalies included broad thumbs, broad great toes with varus deformity, complete 3/4 cutaneous syndactyly of the right foot and 2/3/4 partial cutaneous syndactyly of the left (Fig. 1B, C). X-ray and ultrasound examination of the skull showed bilateral synostosis of the coronal suture and revealed agenesis of the corpus callosum. Blood tests showed low level of cortisol. Reconstructive operative procedure of the skull was carried out at 4 months of age. Based on the phenotypic signs, the diagnosis of Saethre–Chotzen syndrome was raised. However, sequencing of TWIST1 gene coding region and analysis for p. Pro250Arg mutation of FGFR3 gave normal results. The index patient was four years old when detailed clinical genetic examination on her and her family members was performed. On examination at 4 years of age, her weight was 16 kg (50th centile), height was 105 cm (75th centile) and occipitofrontal circumference was 47 cm (3–10th centile). Her somatic and mental development seemed to be normal; the skull was only mildly brachycephalic, so further reconstructive operative intervention was not necessary. Xray picture of the hands showed clinodactyly of the little fingers (Fig. 1B). The father of the index patient was 37 years old at the time of examination. He showed some dysmorphic signs and limb abnormalities as follows: asymmetry of the skull and face (apparent plagiocephaly), mild ptosis of the left upper eyelid, laterally flared eyebrows, prominent nose with a bulbous tip, long philtrum, downturned corners of the mouth. His fingers were apparently normal, only mild clinodactyly of the second fingers could be observed. The great toes were broad with triangular-shaped nails, while the nails on other toes were apparently round. Syndactyly was not present (Fig. 2A–D). The 34-year-old paternal uncle of the index patient had a mild acrocephaly, long philtrum, long ears with prominence of the upper one-third of the lobes. No abnormalities of the upper limbs were seen. His feet and the great toes were broad, and bilateral, partial 2/3 cutaneous syndactyly was observed (Fig. 2E–H). He has one healthy daughter. The 58-year-old paternal grandmother of the index patient had mild brachycephaly, laterally flared eyebrows, mild ptosis of the left upper lid, convergent strabism, prominent nose with a bulbous tip, mandibular prognathism and long, posteriorly rotated ears. Clinodactyly of the 2nd fingers were more obvious than in the proband’s father. She had triangular-shaped nails on the broad 1st toes and had apparently short metatarsal bones. Syndactyly was not present (Fig. 2I–L). She told us that her mother had syndactyly of her toes, as well, but she was not accessible for clinical examination. The 60-year-old brother of the paternal grandmother had mild brachycephaly, laterally sparse, “mephistophean” eyebrows, deep nasolabial folds, convex nasal ridge, mandibular prognathism, long
3177
FIG. 1. Craniofacial and digital features of the proband. A. Frontal and lateral view. Note brachycephaly, high forehead, depressed nasal bridge, long philtrum, low-set ears, and broad thumbs. B. X-ray picture of the hands at four years of age. Note clinodactyly of the little fingers. C. Photographs of the feet. Note radially deviated great toes and syndactyly of 3/4 toes on the right and 2/3/4 on the left.
ears with large lobules. He had clinodactyly of his 2nd and 5th fingers, and clubbing of the distal phalanges. Broad feet and great toes, apparently short metatarsal bones, short and irregularly placed toes, partial 2/3 syndactyly on the left foot were observed (Fig. 2M– P). He has two daughters, the elder one has syndactylies on both feet, but she was not accessible for clinical examination. Due to the mild skull deformities in the family members, suspicion of craniosynostosis has never been raised before, therefore X-rays or CT images are not available. Figure 3 shows the pedigree of the family. Based on the clinical signs (especially the deviated, broad great toes in the index patient), Pfeiffer syndrome was suspected.
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FIG. 2. Craniofacial and digital features of the family members. A–D, father: note plagoicephaly, asimmetry of the face, mild dysmorphic features, clinodactyly of the second fingers and broad great toes. E–H, paternal uncle: note mild acrocephaly and 2/3 partial syndactyly on both feet. I–L, paternal grandmother: note mild brachycephaly and dysmorphic signs, clinodactyly of the second fingers and broad great toes. M–P, brother of the paternal grandmother: note mild brachycephaly and dysmorphic signs, clinodactyly of the second and fifth fingers, broad great toes and partial 3/4 syndactyly of the left foot.
Molecular Analysis
FIG. 3. Pedigree of the family. Black symbols represent the affected individuals. Arrow indicates the index patient, and asterisks denote family members suspected to have Pfeiffer syndrome, but they were not accessible for clinical and molecular genetic examination.
Peripheral blood samples of the index patient and her family members presenting clinical signs were referred to the Clinical Genetic Center, Department of Pediatrics, University of Debrecen for molecular genetic analysis of Pfeiffer syndrome. Genomic DNA was extracted using QIAamp DNA Blood Mini kit (Qiagen, Germantown, MD), and amplification of exon IIIa and IIIc of FGFR2 and exon IIIa of FGFR1 was performed by polymerase chain reaction (PCR) with previously published primer pairs and conditions [Kan et al., 2002; Baroni et al., 2005; Seto et al., 2007]. PCR products were sequenced on an ABI 3100 sequencer with Big Dye Terminator v3.1 cycle sequencing kit (Applied Biosystems, Foster City, CA). Sequence analysis of exon IIIa and IIIc of FGFR2 in the index patient gave normal result, while a heterozygous c.755C > G (p. Pro252Arg) mutation was detected in exon IIIa of FGFR1 supporting the diagnosis of Pfeiffer syndrome type 1. The same heterozygous missense mutation was detected in all affected family members.
BESSENYEI ET AL.
DISCUSSION Pfeiffer syndrome is a rare autosomal dominant disorder characterized by craniosynostosis, facial dysmorphic features and limb abnormalities. PS patients have been reported to show a high clinical variability and genetic heterogenity. Some mutations (e.g., FGFR2 p. Tyr340Cys or p.Cys342Arg) cause severe clinical manifestations, while others (e.g., FGFR1 p.Pro252Arg) result in mild phenotype only [Muenke et al., 1994; Lajeunie et al., 2006]. Regarding head shape, cloverleaf skull configuration and apparently normal skull may represent the two ends of the phenotypic spectrum. Several authors published PS cases with distinct mutations without craniosynostosis [Ettinger et al., 2013; Jay et al., 2013]. Interestingly, the absence of craniosynostosis has been reported not only in mild type 1 PS, but in type 2 where severe cranial manifestation is an otherwise constant finding [Ettinger et al., 2013]. In 1994 Muenke et al. identified the FGFR1 gene on chromosomal region 8p11 to be associated with Pfeiffer syndrome. A specific mutation, p.Pro252Arg, located in the IgII-III linker region of FGFR1, has been reported to cause mild symptoms making the diagnosis rather difficult in many cases. FGFR1 p.Pro252Arg mutation without craniosynostosis has been reported on two occasions in the literature supporting the evidence of variable expressivity of the syndome [Rossi et al., 2003; Hackett and Rowe, 2006]. The example of the here-reported-family supports some already existing observations on the wide-ranged manifestations of type 1 PS with often mild, hardly detectable morphological signs, and underpins the necessity of a detailed evaluation of the pedigree and clinical examination of previous generations with seemingly unaffected individuals. Our study and previously published cases suggest that the penetrance of craniosynostosis may be reduced in type 1, especially in FGFR1 related cases. We conclude that classical features of Pfeiffer syndrome may manifest themselves only after several generations, but attenuated phenotypes may call the attention to the underlying genetic condition. Therefore, precise phenotyping and carefully indicated molecular testing in providing adequate genetic counseling are of paramount importance.
REFERENCES Baroni T, Carinci P, Lilli C, Bellucci C, Aisa MC, Scapoli L, Volinia S, Carinci F, Pezzetti F, Calvitti M, Farina A, Conte C, Bodo M. 2005. P253R fibroblast growth factor receptor-2 mutation induces RUNX2 transcript variants and calvarial osteoblast differentiation. J Cell Physiol 202:524–535.
3179 Cohen MM Jr. 1993. Pfeiffer syndrome update, clinical subtypes, and guidelines for differential diagnosis. Am J Med Genet 45:300–307. Ettinger N, Williams M, Philips JA III. 2013. Variable expressivity and clinical heterogeneity can complicate the diagnosis and management of Pfeiffer syndrome. J Craniofac Surg 24:1829–1832. Hackett A, Rowe L. 2006. FGFR1 Pfeiffer syndrome without craniosynostosis: An additional case report. Clin Dysmorphol 15:207–210. Jay S, Wiberg A, Swan M, Lester T, Williams LJ, Taylor IB, Johnson D, Wilkie AOM. 2013. The fibroblast growth factor receptor 2p. Ala172Phe Mutation in Pfeiffer syndrome – History repeating itself. Am J Med Genet 161:1158–1163. Kan SH, Elanko N, Johnson D, Cornejo-Roldan L, Cook J, Reich EW, Tomkins S, Verloes A, Twigg SRF, Rannan-Eliya S, McDonald-McGinn DM, Zackai EH, Wall SA, Muenke M, Wilkie AOM. 2002. Genomic screening of fibroblast growth-factor receptor 2 reveals a wide spectrum of mutations in patients with syndromic craniosynostosis. Am J Hum Genet 70:472–786. Lajeunie E, Heuertz S, El Ghouzzi V, Martinovic J, Renier D, Le Merrer M, Bonaventure J. 2006. Mutation screening in patients with syndromic carniosynostoses indicates that a limited number of recurrent FGFR2 mutations accounts for severe forms of Pfeiffer syndrome. Eur J Hum Genet 14:289–298. Muenke M, Schell U, Hehr A, Robin NH, Losken HW, Schinzel A, Pulleyn LJ, Rutland P, Reardon W, Malcolm S, Winter RM. 1994. A common mutation in the fibroblast growth factor receptor 1 gene in Pfeiffer syndrome. Nat Genet 8:269–274. Pfeiffer RA. 1964. Dominant Hereditary acrocephalosyndactylia. Z Kinderheilkd 90:301–320. Robin NH, Scott JA, Arnold JE, Goldstein JA, Shilling BB, Marion RW, Cohen MM Jr. 1998. Favorable prognosis for children with Pfeiffer syndrome types 2 and 3: Implications for classification. Am J Med Genet 75:240–244. Rossi M, Jones RL, Norbury G, Bloch-Zupan A, Winter RM. 2003. The appearance of the feet in Pfeiffer syndrome caused by FGFR1 P252R mutation. Clin Dysmorphol 12:269–274. Schell U, Hehr A, Feldman GJ, Robin NH, Zackai EH, de Die-Smulders C, Viskochil DH, Stewart JM, Wolff G, Ohashi H, Price RA, Cohen MM Jr, Muenke M. 1995. Mutations in FGFR1 and FGFR2 cause familial and sporadic Pfeiffer syndrome. Hum Mol Genet 4:323–328. Seto ML, Hing AV, Chang J, Hu M, Kapp-Simon KA, Patel PK, Burton BK, Kane AA, Smyth MD, Hopper R, Ellenbogen RG, Stevenson K, Speltz ML, Cunningham ML. 2007. Isolated sagittal and coronal craniosynostosis associated with TWIST box mutations. Am J Med Genet 143:678–686. Teebi AS, Kennedy S, Chun K, Ray PN. 2002. Severe and mild phenotypes in Pfeiffer syndrome with splice acceptor mutations in exon IIIc of FGFR2. Am J Med Genet 107:43–47.
Variable Expressivity of Pfeiffer Syndrome in a Family With FGFR1 p.Pro252Arg Mutation Bea´ta Bessenyei,1* Mariann Tihanyi,2 Marianna Hartwig,2 Katalin Szakszon,3 and ´Eva Ola´h3 1
Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
2
Genetic Laboratory, Hospital of Zala County, Zalaegerszeg, Hungary
3
Department of Pediatrics, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
Manuscript Received: 26 March 2014; Manuscript Accepted: 20 August 2014
Pfeiffer syndrome is an autosomal dominant disorder classically characterized by craniosynostosis, facial dysmorphism and limb anomalies. The majority of cases are caused by mutations in the fibroblast growth factor receptor 2 (FGFR2) gene. A specific, rare mutation p.Pro252Arg, located between the second and third extracellular immunoglobulin-like domain of FGFR1, is associated with mild clinical signs. We report on a three-generation family with five members having a heterozygous FGFR1 p. Pro252Arg mutation. Phenotypic features within the family showed high variability from the apparently normal skull and limbs to the characteristic brachycephaly and digital anomalies. The typical features of Pfeiffer syndrome appeared only in the third generation allowing us to unveil the syndrome in several further family members in two previous generations. Variable expressivity can complicate the recognition of Pfeiffer syndrome, principally the mild type 1, requiring careful phenotyping and genetic counseling. Ó 2014 Wiley Periodicals, Inc.
Key words: Pfeiffer syndrome; craniosynostosis; FGFR1; syndactyly; clinodactyly
How to Cite this Article: Bessenyei B, Tihanyi M, Hartwig M, Szakszon K, Ola´h E´. 2014. Variable expressivity of pfeiffer syndrome in a family with FGFR1 p.Pro252Arg mutation. Am J Med Genet Part A 164A:3176–3179.
et al., 1995]. FGFR2 mutations occuring in all types of PS are frequently detected in exons IIIa and IIIc and they are found in the great majority of PS cases. A specific mutation, p.Pro252Arg of FGFR1, is quite rare in this syndrome and associates with type 1 PS. Patients with this mutation usually have very mild craniofacial features with variable presence of craniosynostosis [Rossi et al., 2003; Hackett and Rowe, 2006]. Hereby we report a threegeneration family with PS type 1 associated with the specific FGFR1 p.Pro252Arg mutation. The mutation was detected in five members of the family. The phenotype proved to be highly variable, from the apparently normal skull to the obvious brachycephaly and dysmorphic features. Abnormalities of the digits especially on the feet were consistently present in all family members affected by the mutation.
INTRODUCTION Pfeiffer syndrome (PS) is an autosomal dominantly inherited craniosynostosis disorder affecting about 1 in 100,000 individuals. It is clinically and genetically heterogeneous with variable clinical severity [Robin et al., 1998; Teebi et al., 2002; Lajeunie et al., 2006]. Typical symptoms include abnormal skull shape, facial dysmorphism and limb anomalies. The characteristic cranial features are brachycephaly due to craniosynostosis, high forehead, midface hypoplasia, convex nasal ridge, depressed nasal bridge, hypertelorism and ocular proptosis [Pfeiffer, 1964]. Patients have broad thumbs and big toes usually deviated from the other digits. Syndactyly of the second and third fingers and toes is also common [Rossi et al., 2003]. Pfeiffer syndrome patients may manifest additional abnormalities including neurological, visual, auditory, and visceral problems. Based on the severity of the phenotype, PS can be divided into three clinical subtypes of diagnostic and prognostic significance [Cohen, 1993]. Pfeiffer syndrome is caused by activating mutations in the fibroblast growth factor receptor (FGFR) 1 and 2 genes [Schell
Ó 2014 Wiley Periodicals, Inc.
CLINICAL REPORT The index patient, a female newborn was referred to the genetic counseling of the Hospital of Zala County, Hungary. She was the first child of no-consanguineous Caucasian parents. The father was 33, the mother was 26 years old at the time of conception. The mother had one healthy child from her previous relationship. During Conflict of interest disclosure: The authors have no conflict of interest and disclose any financial interest. Correspondence to: Bea´ta Bessenyei, Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary 98. Nagyerdei krt., Debrecen H-4032. E-mail: [email protected] Article first published online in Wiley Online Library (wileyonlinelibrary.com): 23 September 2014 DOI 10.1002/ajmg.a.36774
3176
BESSENYEI ET AL. pregnancy, the mother received fraxiparine treatment due to muscle treat, and was operated on to correct aortic insufficiency. The index patient was delivered spontaneously at term with a birth weight of 3,200 g (50th centile), length 48 cm (10–25th centile) and occipitofrontal circumference 32 cm (10–25th centile). Her abnormal skull configuration and facial dysmorphism were noted already at birth: she had brachy- and acrocephaly, high forehead, wide and depressed nasal bridge, hypertelorism, flat bulbous nose-tip with a broad nasal base and thick alae nasi, anteverted nares, long philtrum, thin lip vermilion, horizontal groove under the lower lip, low-set ears with overfolded helices (Fig. 1A). Limb anomalies included broad thumbs, broad great toes with varus deformity, complete 3/4 cutaneous syndactyly of the right foot and 2/3/4 partial cutaneous syndactyly of the left (Fig. 1B, C). X-ray and ultrasound examination of the skull showed bilateral synostosis of the coronal suture and revealed agenesis of the corpus callosum. Blood tests showed low level of cortisol. Reconstructive operative procedure of the skull was carried out at 4 months of age. Based on the phenotypic signs, the diagnosis of Saethre–Chotzen syndrome was raised. However, sequencing of TWIST1 gene coding region and analysis for p. Pro250Arg mutation of FGFR3 gave normal results. The index patient was four years old when detailed clinical genetic examination on her and her family members was performed. On examination at 4 years of age, her weight was 16 kg (50th centile), height was 105 cm (75th centile) and occipitofrontal circumference was 47 cm (3–10th centile). Her somatic and mental development seemed to be normal; the skull was only mildly brachycephalic, so further reconstructive operative intervention was not necessary. Xray picture of the hands showed clinodactyly of the little fingers (Fig. 1B). The father of the index patient was 37 years old at the time of examination. He showed some dysmorphic signs and limb abnormalities as follows: asymmetry of the skull and face (apparent plagiocephaly), mild ptosis of the left upper eyelid, laterally flared eyebrows, prominent nose with a bulbous tip, long philtrum, downturned corners of the mouth. His fingers were apparently normal, only mild clinodactyly of the second fingers could be observed. The great toes were broad with triangular-shaped nails, while the nails on other toes were apparently round. Syndactyly was not present (Fig. 2A–D). The 34-year-old paternal uncle of the index patient had a mild acrocephaly, long philtrum, long ears with prominence of the upper one-third of the lobes. No abnormalities of the upper limbs were seen. His feet and the great toes were broad, and bilateral, partial 2/3 cutaneous syndactyly was observed (Fig. 2E–H). He has one healthy daughter. The 58-year-old paternal grandmother of the index patient had mild brachycephaly, laterally flared eyebrows, mild ptosis of the left upper lid, convergent strabism, prominent nose with a bulbous tip, mandibular prognathism and long, posteriorly rotated ears. Clinodactyly of the 2nd fingers were more obvious than in the proband’s father. She had triangular-shaped nails on the broad 1st toes and had apparently short metatarsal bones. Syndactyly was not present (Fig. 2I–L). She told us that her mother had syndactyly of her toes, as well, but she was not accessible for clinical examination. The 60-year-old brother of the paternal grandmother had mild brachycephaly, laterally sparse, “mephistophean” eyebrows, deep nasolabial folds, convex nasal ridge, mandibular prognathism, long
3177
FIG. 1. Craniofacial and digital features of the proband. A. Frontal and lateral view. Note brachycephaly, high forehead, depressed nasal bridge, long philtrum, low-set ears, and broad thumbs. B. X-ray picture of the hands at four years of age. Note clinodactyly of the little fingers. C. Photographs of the feet. Note radially deviated great toes and syndactyly of 3/4 toes on the right and 2/3/4 on the left.
ears with large lobules. He had clinodactyly of his 2nd and 5th fingers, and clubbing of the distal phalanges. Broad feet and great toes, apparently short metatarsal bones, short and irregularly placed toes, partial 2/3 syndactyly on the left foot were observed (Fig. 2M– P). He has two daughters, the elder one has syndactylies on both feet, but she was not accessible for clinical examination. Due to the mild skull deformities in the family members, suspicion of craniosynostosis has never been raised before, therefore X-rays or CT images are not available. Figure 3 shows the pedigree of the family. Based on the clinical signs (especially the deviated, broad great toes in the index patient), Pfeiffer syndrome was suspected.
3178
AMERICAN JOURNAL OF MEDICAL GENETICS PART A
FIG. 2. Craniofacial and digital features of the family members. A–D, father: note plagoicephaly, asimmetry of the face, mild dysmorphic features, clinodactyly of the second fingers and broad great toes. E–H, paternal uncle: note mild acrocephaly and 2/3 partial syndactyly on both feet. I–L, paternal grandmother: note mild brachycephaly and dysmorphic signs, clinodactyly of the second fingers and broad great toes. M–P, brother of the paternal grandmother: note mild brachycephaly and dysmorphic signs, clinodactyly of the second and fifth fingers, broad great toes and partial 3/4 syndactyly of the left foot.
Molecular Analysis
FIG. 3. Pedigree of the family. Black symbols represent the affected individuals. Arrow indicates the index patient, and asterisks denote family members suspected to have Pfeiffer syndrome, but they were not accessible for clinical and molecular genetic examination.
Peripheral blood samples of the index patient and her family members presenting clinical signs were referred to the Clinical Genetic Center, Department of Pediatrics, University of Debrecen for molecular genetic analysis of Pfeiffer syndrome. Genomic DNA was extracted using QIAamp DNA Blood Mini kit (Qiagen, Germantown, MD), and amplification of exon IIIa and IIIc of FGFR2 and exon IIIa of FGFR1 was performed by polymerase chain reaction (PCR) with previously published primer pairs and conditions [Kan et al., 2002; Baroni et al., 2005; Seto et al., 2007]. PCR products were sequenced on an ABI 3100 sequencer with Big Dye Terminator v3.1 cycle sequencing kit (Applied Biosystems, Foster City, CA). Sequence analysis of exon IIIa and IIIc of FGFR2 in the index patient gave normal result, while a heterozygous c.755C > G (p. Pro252Arg) mutation was detected in exon IIIa of FGFR1 supporting the diagnosis of Pfeiffer syndrome type 1. The same heterozygous missense mutation was detected in all affected family members.
BESSENYEI ET AL.
DISCUSSION Pfeiffer syndrome is a rare autosomal dominant disorder characterized by craniosynostosis, facial dysmorphic features and limb abnormalities. PS patients have been reported to show a high clinical variability and genetic heterogenity. Some mutations (e.g., FGFR2 p. Tyr340Cys or p.Cys342Arg) cause severe clinical manifestations, while others (e.g., FGFR1 p.Pro252Arg) result in mild phenotype only [Muenke et al., 1994; Lajeunie et al., 2006]. Regarding head shape, cloverleaf skull configuration and apparently normal skull may represent the two ends of the phenotypic spectrum. Several authors published PS cases with distinct mutations without craniosynostosis [Ettinger et al., 2013; Jay et al., 2013]. Interestingly, the absence of craniosynostosis has been reported not only in mild type 1 PS, but in type 2 where severe cranial manifestation is an otherwise constant finding [Ettinger et al., 2013]. In 1994 Muenke et al. identified the FGFR1 gene on chromosomal region 8p11 to be associated with Pfeiffer syndrome. A specific mutation, p.Pro252Arg, located in the IgII-III linker region of FGFR1, has been reported to cause mild symptoms making the diagnosis rather difficult in many cases. FGFR1 p.Pro252Arg mutation without craniosynostosis has been reported on two occasions in the literature supporting the evidence of variable expressivity of the syndome [Rossi et al., 2003; Hackett and Rowe, 2006]. The example of the here-reported-family supports some already existing observations on the wide-ranged manifestations of type 1 PS with often mild, hardly detectable morphological signs, and underpins the necessity of a detailed evaluation of the pedigree and clinical examination of previous generations with seemingly unaffected individuals. Our study and previously published cases suggest that the penetrance of craniosynostosis may be reduced in type 1, especially in FGFR1 related cases. We conclude that classical features of Pfeiffer syndrome may manifest themselves only after several generations, but attenuated phenotypes may call the attention to the underlying genetic condition. Therefore, precise phenotyping and carefully indicated molecular testing in providing adequate genetic counseling are of paramount importance.
REFERENCES Baroni T, Carinci P, Lilli C, Bellucci C, Aisa MC, Scapoli L, Volinia S, Carinci F, Pezzetti F, Calvitti M, Farina A, Conte C, Bodo M. 2005. P253R fibroblast growth factor receptor-2 mutation induces RUNX2 transcript variants and calvarial osteoblast differentiation. J Cell Physiol 202:524–535.
3179 Cohen MM Jr. 1993. Pfeiffer syndrome update, clinical subtypes, and guidelines for differential diagnosis. Am J Med Genet 45:300–307. Ettinger N, Williams M, Philips JA III. 2013. Variable expressivity and clinical heterogeneity can complicate the diagnosis and management of Pfeiffer syndrome. J Craniofac Surg 24:1829–1832. Hackett A, Rowe L. 2006. FGFR1 Pfeiffer syndrome without craniosynostosis: An additional case report. Clin Dysmorphol 15:207–210. Jay S, Wiberg A, Swan M, Lester T, Williams LJ, Taylor IB, Johnson D, Wilkie AOM. 2013. The fibroblast growth factor receptor 2p. Ala172Phe Mutation in Pfeiffer syndrome – History repeating itself. Am J Med Genet 161:1158–1163. Kan SH, Elanko N, Johnson D, Cornejo-Roldan L, Cook J, Reich EW, Tomkins S, Verloes A, Twigg SRF, Rannan-Eliya S, McDonald-McGinn DM, Zackai EH, Wall SA, Muenke M, Wilkie AOM. 2002. Genomic screening of fibroblast growth-factor receptor 2 reveals a wide spectrum of mutations in patients with syndromic craniosynostosis. Am J Hum Genet 70:472–786. Lajeunie E, Heuertz S, El Ghouzzi V, Martinovic J, Renier D, Le Merrer M, Bonaventure J. 2006. Mutation screening in patients with syndromic carniosynostoses indicates that a limited number of recurrent FGFR2 mutations accounts for severe forms of Pfeiffer syndrome. Eur J Hum Genet 14:289–298. Muenke M, Schell U, Hehr A, Robin NH, Losken HW, Schinzel A, Pulleyn LJ, Rutland P, Reardon W, Malcolm S, Winter RM. 1994. A common mutation in the fibroblast growth factor receptor 1 gene in Pfeiffer syndrome. Nat Genet 8:269–274. Pfeiffer RA. 1964. Dominant Hereditary acrocephalosyndactylia. Z Kinderheilkd 90:301–320. Robin NH, Scott JA, Arnold JE, Goldstein JA, Shilling BB, Marion RW, Cohen MM Jr. 1998. Favorable prognosis for children with Pfeiffer syndrome types 2 and 3: Implications for classification. Am J Med Genet 75:240–244. Rossi M, Jones RL, Norbury G, Bloch-Zupan A, Winter RM. 2003. The appearance of the feet in Pfeiffer syndrome caused by FGFR1 P252R mutation. Clin Dysmorphol 12:269–274. Schell U, Hehr A, Feldman GJ, Robin NH, Zackai EH, de Die-Smulders C, Viskochil DH, Stewart JM, Wolff G, Ohashi H, Price RA, Cohen MM Jr, Muenke M. 1995. Mutations in FGFR1 and FGFR2 cause familial and sporadic Pfeiffer syndrome. Hum Mol Genet 4:323–328. Seto ML, Hing AV, Chang J, Hu M, Kapp-Simon KA, Patel PK, Burton BK, Kane AA, Smyth MD, Hopper R, Ellenbogen RG, Stevenson K, Speltz ML, Cunningham ML. 2007. Isolated sagittal and coronal craniosynostosis associated with TWIST box mutations. Am J Med Genet 143:678–686. Teebi AS, Kennedy S, Chun K, Ray PN. 2002. Severe and mild phenotypes in Pfeiffer syndrome with splice acceptor mutations in exon IIIc of FGFR2. Am J Med Genet 107:43–47.
