CLINICAL REPORT
A Familial GLI2 Deletion (2q14.2) not Associated with the Holoprosencephaly Syndrome Phenotype Ulrike Kordaß,1 Carmen Schro¨der,2 Miriam Elbracht,3 Lukas Soellner,3 and Thomas Eggermann3* 1
Praxis fu¨r Humangenetik, Greifswald, Germany
2
Childrens, Hospital, University of Greifswald, Greifswald, Germany
3
Institute of Human Genetics, University Hospital RWTH Aachen University, Aachen, Germany
Manuscript Received: 20 August 2014; Manuscript Accepted: 28 December 2014
Molecular alterations of the GLI2 gene in 2q14.2 are associated with features from the holoprosencephaly spectrum. However, the phenotype is extremely variable, ranging from unaffected mutation heterozygotes to isolated or combined pituitary hormone deficiency, and to patients with a phenotype that overlaps with holoprosencephaly, including abnormal pituitary gland formation/function, craniofacial dysmorphisms, branchial arch anomalies, and polydactyly. Although many point mutations within the GLI2 gene have been identified, large (sub) microscopic deletions affecting 2q14.2 are rare. We report on a family with a 4.3 Mb deletion in 2q14 affecting GLI2 without any dysmorphologic features belonging to the holoprosencephaly spectrum. This family confirms the incomplete penetrance of genomic disturbances affecting the GLI2 gene. However, the family presented here is unique as none of the three identified individuals with a GLI2 deletion showed any typical signs of holoprosencephaly, whereas all patients reported so far were referred for genetic testing because at least one member exhibited holoprosencephaly and related features. Ó 2015 Wiley Periodicals, Inc.
Key words: GLI2 gene; microdeletion; chromosome 2q14.2; holoprosencephaly; growth retardation
INTRODUCTION GLI2 (gli-kruppel family member 2) is a zinc-finger transcription factor in the Sonic Hedgehog signaling pathway, acting early in ventral forebrain and pituitary development. Haploinsufficiency of GLI2 in 2q14.2 caused by point mutations has been reported in patients with features of the holoprosencephaly (HPE) spectrum. However, the phenotype is highly variable, ranging from unaffected heterozygotes to isolated or combined pituitary hormone deficiency, and to patients with a mild HPE phenotype including abnormal pituitary gland formation/function, craniofacial dysmorphism, branchial arch anomalies, and polydactyly (for review see: [Cohen, 2012; Flemming et al., 2013; Franc¸a et al., 2013]). Meanwhile, many point mutations within GLI2 have been identified in studies of distinct phenotypic cohorts, but large (sub) microscopic deletions affecting 2q14.2 are rare (for review see
Ó 2015 Wiley Periodicals, Inc.
How to Cite this Article: Kordaß U, Schro¨der C, Elbracht M, Soellner L, Eggermann T. 2015. A familial GLI2 deletion (2q14.2) not associated with the holoprosencephaly syndrome phenotype. Am J Med Genet Part A 167A:1121–1124.
[Kevelam et al., 2012]). The latter group consists of eight individuals, but only one of them was detected by molecular karyotyping [Kevelam et al., 2012]. Interestingly, these patients had a mild HPE spectrum phenotype, but in none of them were brain features of HPE detected.
CLINICAL REPORT We report a 25-year-old German woman referred for genetic testing because of growth retardation (150 cm, 2.47 SD; 34 kg, BMI 15.11 kg/m2) and her wish to have children. The patient was the first child of a nonconsanguineous German couple. The pregnancy was uneventful, the patient was born at term. Birth weight was 2570 g (2.14 SD), length 47 cm (2.14 SD). Microcephaly was noted (37 cm, 2.90 SD) at 3 months. Postnatally, a ventricular septal defect (VSD) and atrial septal defect type II (ASDII) were diagnosed. When she was 1 year old her left kidney was removed because it was nonfunctional and multicystic. Growth and weight retardation persisted postnatally (length: Conflict of interest: The authors declare that they do not have any conflict of interest. Grant sponsor: Bundesministerium fu¨r Bildung und Forschung (Network “Imprinting Diseases,”); Grant number: 01GM1114C. Correspondence to: Thomas Eggermann, Ph.D, Department of Human Genetics, University Hospital, RWTH Aachen, Pauwelsstr. 30, D-52074 Aachen, Germany. E-mail: [email protected] Article first published online in Wiley Online Library (wileyonlinelibrary.com): 28 March 2015 DOI 10.1002/ajmg.a.36972
1121
It should be noted that the majority of patients have been identified by conventional cytogenetic analyses; therefore, the breakpoints may not be accurate. (NA, not assessed; (), probably not present).
Temporal myelinisation disturbance Paternal 2q14.2q14.3 Present case
SNP array
Paternal De-novo De-novo Paternal 2q14.1-22.1 2q14.2-22.1 2q14.2-21.3 2q14.2 Baker et al. [2001] Gustavsson et al. [2006] Peng et al. [2006] Kevelam et al. [2012]
Cytogenetics Cytogenetics aCGH aCGH
De-novo 2q13-q21 Davis et al. [1991]
Cytogenetics
De-novo NA 2q14-q21 2q14-q21 Lucas et al. [1987] Frydman et al. [1989]
Cytogenetics Cytogenetics
()
NA þ, single incisor þ, Cleft lip and palate Present case þ þ NA NA þ þ/ þ þ NA þ
þ NA
NA NA þ NA NA
Polydactyly þ Heterotaxy Intellectual disability þ GH deficiency NA
Brain features Agenesis corpus callosum Agenesis corpus callosum Agenesis corpus callosum, Dandy Walker malformation NA NA Ventriculomegaly Pituitary anomaly Origin De-novo Method Cytogenetics Deleted region/ breakpoints 2q12-q14 Patient Antich et al. [1981]
TABLE I. Overview of the Major Clinical Findings in Patients Heterozygous for 2q14 Deletions Affecting GLI2 From Kevelam et al. [2012].
þ
AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Facial dysmorphisms þ, Cleft lip and palate þ þ
1122
74 cm, 1.80 SD, at 1 4/12 years to 103 cm, 2.91 SD, at 6 years). As a result, at the age of 6 years she underwent endocrinologic evaluation. Measurement of IGF1 and IGFBP3 showed reduced levels (IGF1: 28.8 ng/ml[71.20–252.00], IGFBP3: 1.6 mg/ml [2.50–4.05]). However, an arginine test gave a normal result (peak growth hormone [GH] level 21.3 mg/L). An insulin tolerance test yielded a GH value of 6.90 mg/L in maximum (cut-off 8). Overnight measurement of GH indicated a neurosecretory dysfunction, but there were no other endocrine dysfunctions. At the age of 6 years, recombinant growth hormone (rGH) therapy was started, and growth seemed to improve (147.5 cm, 2.11 SD at the age of 13 8/12). Menarche occurred at 13 years and her height at 25 years was 150 cm (2.47 SD) indicating that there was no apparent benefit from rGH. With the exception of short stature, further characteristics associated with GLI2 point mutations (for review see [Kevelam et al., 2012]) were not present. In fact, the patient showed scoliosis and several facial dysmorphic features, i.e., a high anterior hairline, a short philtrum, a pointed chin, and a long nose. Esotropia was noted. Cranial MRI showed abnormal temporal myelinization. Psychomotoric development was apparently normal, she is currently unemployed but has a qualification as an office employee. Formal intelligence tests were not performed. Family history showed two abortions (one with twins) of her mother. Clinical data and pictures available from the grandmother and the deceased father did not identify any phenotypic abnormalities. Her father died at the age of 33 from complications of diabetes mellitus. The height of her mother was 161 cm, her father was 173 cm tall (1.16 SD) and thin (60 kg, BMI 20.76). The paternal grandmother was 156 cm tall (2.47 SD), the grandfather 180 cm tall (þ0.28 SD). Grandmaternal weight was (70 kg, BMI 31.11) whereas the father was of normal weight. Due to the severe growth retardation and other minor signs, Silver–Russell syndrome (SRS) was considered but was not probable because of the microcephaly. Indeed, genetic testing for chromosome 11p15 imbalances and methylation defects as well as maternal uniparental disomy of chromosome 7 by MS-MLPA (SALSA Kit ME30, MRC Holland, Amsterdam/NL) and MSSNuPE [Begemann et al., 2012] was negative. The subsequent molecular karyotyping with an Affymetrix GeneChip1GenomeWide Human SNP 6.0-Array showed a heterozygous 4.3 Mb deletion in 2q14.2q14.3 (hg19: chr2:121642461–125977825) (Fig. 1a), including 12 of the 13 exons of the GLI2 and six additional genes. The deletion was confirmed by a qPCR approach. MLPA with the P187-HPE SALSA kit (MRC Holland) confirmed the heterozygous deletion of exons 2–13 of the GLI2 gene, whereas exon 1 was not affected (Fig. 1b). We could exclude the deletion in the patients mother. As the father was already dead we tested DNA samples of the paternal grandparents. The deletion was identified in the paternal grandmother. The work was approved by the Ethical Review board of the University Hospital of the RWTH Aachen, Germany.
DISCUSSION The identification of a 4.3 Mb deletion in 2q14 in a patient and her family without any features of the HPE spectrum confirms the
KORDAß ET AL.
1123
FIG. 1. Identification of the 2q14.2 deletion in the patient presented here. (a) SNP array signal distribution pattern. The figures include the schematic presentation of the copy number segments, gene entries in this region, distribution of markers, and physical positions. (b) Result of the P187-HPE MLPA analysis confirming the heterozygous deletion of the exons 2–13 of GLI2.
incomplete penetrance reported for both point mutation and genomic imbalances affecting GLI2 [Roessler et al., 2003; Kevelam et al., 2012]. However, the family presented here is distinctive as none of the three identified heterozygote family members showed any typical signs of HPE, whereas all patients reported so far were referred for genetic testing because at least one member exhibiting HPE and related features (Table I). Apart from the unspecific feature of growth retardation, the only clinical sign compatible with HPE was the growth hormone deficiency in childhood, but in adulthood, pituitary hormone levels were in the normal range (Table I). However, the significance of the deletion in the patient presented here is uncertain. As the affected chromosomal region includes six other genes, one might assume that one of them influences and modifies the phenotype. Nevertheless, the two other heterozygotes in the family do not show the same phenotype. Indeed, the paternal grandmother is of small stature, whereas the deceased father was thin. The 2q14 deletion in the patient presented here was different in size (4.3 versus 1.3 Mb) and located more proximally than the aberration reported by Kevelam et al. [2012]. As a result, both deletions share only two genes, GLI2 and TFCP2L1. As the patient presented here did not show any signs of heterotaxy, we can confirm the suggestion of Kevelam et al. [2012] that the latter gene is not involved in the etiology of that symptom. For the other genes affected by the deletion in the patient, an association with a specific phenotype has been suggested only for the RNU4ATAC gene. However, the patient described here did not show any clinical signs of microcephalic osteodysplastic primordial dwarfism type I, and a heterozygote effect in this autosomal recessive condition has not yet been reported [Abdel-Salam et al., 2012]. In summary, the patient presented here illustrates the need to identify additional families with GLI2 mutations and to document their phenotypes. In the present patient, the persistent growth
retardation was the key feature leading to molecular testing, and therefore, we suggest that molecular karyotyping should be applied in growth retarded patients with only minor dysmorphic features with or without intellectual disability.
ACKNOWLEDGEMENT We thank the family for participating in this study.
REFERENCES Antich J, Carbonell X, Mas J, Clusellas N. 1983. De novo interstitial deletion of the long arm of chromosome 2 in a malformed newborn with a karyotype 46,XY,del(2)(q12q14). Acta Paediatr Scand 72:631–633. Abdel-Salam GM, Abdel-Hamid MS, Issa M, Magdy A, El-Kotoury A, Amr K. 2012. Expanding the phenotypic and mutational spectrum in microcephalic osteodysplastic primordial dwarfism type I. Am J Med Genet A 158A:1455–1461. Baker KL, Rees MI, Thompson PW, Howell RT, Cole TR, Houghes HE, Upadhyaya M, Ravine D. 2001. Chromosome 2 interstitial deletion (del(2)(q14.1q21)) associated with connective tissue laxity and an attention deficit disorder. J Med Genet 38:493–496. Begemann M, Leisten I, Soellner L, Zerres K, Eggermann T, Spengler S. 2012. Use of multi-locus methylation-specific single nucleotide primer extension (MS-SNuPE) technology in diagnostic testing for human imprinted loci. Epigenetics 7:473–481. Cohen LE. 2012. GLI2 mutations as a cause of hypopituitarism. Pediatr Endocrinol Rev 9:706–709. Davis E, Grafe M, Cunniff C, Jones KL, Bogart M. 1991. Interstitial deletion of chromosome 2q associated with ovarian dysgenesis. Clin Genet 35:386–390. Flemming GM, Klammt J, Ambler G, Bao Y, Blum WF, Cowell C, Donaghue K, Howard N, Kumar A, Sanchez J, Stobbe H, Pfa¨ffle RW.
1124 2013. Functional characterization of a heterozygous GLI2 missense mutation in patients with multiple pituitary hormone deficiency. J Clin Endocrinol Metab 93:E567–E575. Franc¸a MM, Jorge AA, Carvalho LR, Costalonga EF, Vasques GA, Leite CC, Mendonca BB, Arnhold IJ. 2010. Novel heterozygous nonsense GLI2 mutations in patients with hypopituitarism and ectopic posterior pituitary lobe without holoprosencephaly. J Clin Endocrinol Metab 95:E3 84–E391. Franc¸a MM, Jorge AA, Carvalho LR, Costalonga EF, Otto AP, Correa FA, Mendonca BB, Arnhold IJ. 2013. Relatively high frequency of non-synonymous GLI2 variants in patients with congenital hypopituitarism without holoprosencephaly. Clin Endocrinol 78:551– 557. Frydman M, Steinberger J, Shabtai F, Katznelson MB, Varsano I. 1989. Interstitial deletion 2q14q21. Am J Med Genet 34:476–479. Gustavsson P, Schoumans J, Staaf J, Jo¨nsson G, Carlsson F, Kristoffersson U, Borg A. 2006. Hemizygosity for chromosome 2q14.2-q22.1 spanning the GLI2 and PROC genes associated with growth hormone deficiency,
AMERICAN JOURNAL OF MEDICAL GENETICS PART A polydactyly, deep vein thrombosis and urogenital abnormalities. Clin Genet 69:441–443. Kevelam SH, van Harssel JJ, van der Zwaag B, Smeets HJ, Paulussen AD, Lichtenbelt KD. 2012. A patient with a mild holoprosencephaly spectrum phenotype and heterotaxy and a 1.3 Mb deletion encompassing GLI2. Am J Med Genet A 158A:166–173. Lucas J, Faivre J, Le Mee F, Hubert S, Pluquailec K, Picard F. 1987. De novo interstitial deletion of the long arm of chromosome 2: 46,XXX, del(2)(q14q21), associated with premature craniosynostosis. Ann Genet 30:33–38. Peng HH, Wang CJ, Wang TH, Chang SD. 2006. Prenatal diagnosis of de novo interstitial 2q14.2–2q21.3 deletion assisted by array-based comparative genomic hybridization: A case report. J Reprod Med 51:438–442. Roessler E, Du YZ, Mullor JL, Casas E, Allen WP, Gillessen-Kaesbach G, Roeder ER, Ming JE, Ruiz i, Altaba A, Muenke M. 2003. Loss-of-function mutations in the human GLI2 gene are associated with pituitary anomalies and holoprosencephaly-like features. Proc Natl Acad Sci USA 100:13424–13429.
A Familial GLI2 Deletion (2q14.2) not Associated with the Holoprosencephaly Syndrome Phenotype Ulrike Kordaß,1 Carmen Schro¨der,2 Miriam Elbracht,3 Lukas Soellner,3 and Thomas Eggermann3* 1
Praxis fu¨r Humangenetik, Greifswald, Germany
2
Childrens, Hospital, University of Greifswald, Greifswald, Germany
3
Institute of Human Genetics, University Hospital RWTH Aachen University, Aachen, Germany
Manuscript Received: 20 August 2014; Manuscript Accepted: 28 December 2014
Molecular alterations of the GLI2 gene in 2q14.2 are associated with features from the holoprosencephaly spectrum. However, the phenotype is extremely variable, ranging from unaffected mutation heterozygotes to isolated or combined pituitary hormone deficiency, and to patients with a phenotype that overlaps with holoprosencephaly, including abnormal pituitary gland formation/function, craniofacial dysmorphisms, branchial arch anomalies, and polydactyly. Although many point mutations within the GLI2 gene have been identified, large (sub) microscopic deletions affecting 2q14.2 are rare. We report on a family with a 4.3 Mb deletion in 2q14 affecting GLI2 without any dysmorphologic features belonging to the holoprosencephaly spectrum. This family confirms the incomplete penetrance of genomic disturbances affecting the GLI2 gene. However, the family presented here is unique as none of the three identified individuals with a GLI2 deletion showed any typical signs of holoprosencephaly, whereas all patients reported so far were referred for genetic testing because at least one member exhibited holoprosencephaly and related features. Ó 2015 Wiley Periodicals, Inc.
Key words: GLI2 gene; microdeletion; chromosome 2q14.2; holoprosencephaly; growth retardation
INTRODUCTION GLI2 (gli-kruppel family member 2) is a zinc-finger transcription factor in the Sonic Hedgehog signaling pathway, acting early in ventral forebrain and pituitary development. Haploinsufficiency of GLI2 in 2q14.2 caused by point mutations has been reported in patients with features of the holoprosencephaly (HPE) spectrum. However, the phenotype is highly variable, ranging from unaffected heterozygotes to isolated or combined pituitary hormone deficiency, and to patients with a mild HPE phenotype including abnormal pituitary gland formation/function, craniofacial dysmorphism, branchial arch anomalies, and polydactyly (for review see: [Cohen, 2012; Flemming et al., 2013; Franc¸a et al., 2013]). Meanwhile, many point mutations within GLI2 have been identified in studies of distinct phenotypic cohorts, but large (sub) microscopic deletions affecting 2q14.2 are rare (for review see
Ó 2015 Wiley Periodicals, Inc.
How to Cite this Article: Kordaß U, Schro¨der C, Elbracht M, Soellner L, Eggermann T. 2015. A familial GLI2 deletion (2q14.2) not associated with the holoprosencephaly syndrome phenotype. Am J Med Genet Part A 167A:1121–1124.
[Kevelam et al., 2012]). The latter group consists of eight individuals, but only one of them was detected by molecular karyotyping [Kevelam et al., 2012]. Interestingly, these patients had a mild HPE spectrum phenotype, but in none of them were brain features of HPE detected.
CLINICAL REPORT We report a 25-year-old German woman referred for genetic testing because of growth retardation (150 cm, 2.47 SD; 34 kg, BMI 15.11 kg/m2) and her wish to have children. The patient was the first child of a nonconsanguineous German couple. The pregnancy was uneventful, the patient was born at term. Birth weight was 2570 g (2.14 SD), length 47 cm (2.14 SD). Microcephaly was noted (37 cm, 2.90 SD) at 3 months. Postnatally, a ventricular septal defect (VSD) and atrial septal defect type II (ASDII) were diagnosed. When she was 1 year old her left kidney was removed because it was nonfunctional and multicystic. Growth and weight retardation persisted postnatally (length: Conflict of interest: The authors declare that they do not have any conflict of interest. Grant sponsor: Bundesministerium fu¨r Bildung und Forschung (Network “Imprinting Diseases,”); Grant number: 01GM1114C. Correspondence to: Thomas Eggermann, Ph.D, Department of Human Genetics, University Hospital, RWTH Aachen, Pauwelsstr. 30, D-52074 Aachen, Germany. E-mail: [email protected] Article first published online in Wiley Online Library (wileyonlinelibrary.com): 28 March 2015 DOI 10.1002/ajmg.a.36972
1121
It should be noted that the majority of patients have been identified by conventional cytogenetic analyses; therefore, the breakpoints may not be accurate. (NA, not assessed; (), probably not present).
Temporal myelinisation disturbance Paternal 2q14.2q14.3 Present case
SNP array
Paternal De-novo De-novo Paternal 2q14.1-22.1 2q14.2-22.1 2q14.2-21.3 2q14.2 Baker et al. [2001] Gustavsson et al. [2006] Peng et al. [2006] Kevelam et al. [2012]
Cytogenetics Cytogenetics aCGH aCGH
De-novo 2q13-q21 Davis et al. [1991]
Cytogenetics
De-novo NA 2q14-q21 2q14-q21 Lucas et al. [1987] Frydman et al. [1989]
Cytogenetics Cytogenetics
()
NA þ, single incisor þ, Cleft lip and palate Present case þ þ NA NA þ þ/ þ þ NA þ
þ NA
NA NA þ NA NA
Polydactyly þ Heterotaxy Intellectual disability þ GH deficiency NA
Brain features Agenesis corpus callosum Agenesis corpus callosum Agenesis corpus callosum, Dandy Walker malformation NA NA Ventriculomegaly Pituitary anomaly Origin De-novo Method Cytogenetics Deleted region/ breakpoints 2q12-q14 Patient Antich et al. [1981]
TABLE I. Overview of the Major Clinical Findings in Patients Heterozygous for 2q14 Deletions Affecting GLI2 From Kevelam et al. [2012].
þ
AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Facial dysmorphisms þ, Cleft lip and palate þ þ
1122
74 cm, 1.80 SD, at 1 4/12 years to 103 cm, 2.91 SD, at 6 years). As a result, at the age of 6 years she underwent endocrinologic evaluation. Measurement of IGF1 and IGFBP3 showed reduced levels (IGF1: 28.8 ng/ml[71.20–252.00], IGFBP3: 1.6 mg/ml [2.50–4.05]). However, an arginine test gave a normal result (peak growth hormone [GH] level 21.3 mg/L). An insulin tolerance test yielded a GH value of 6.90 mg/L in maximum (cut-off 8). Overnight measurement of GH indicated a neurosecretory dysfunction, but there were no other endocrine dysfunctions. At the age of 6 years, recombinant growth hormone (rGH) therapy was started, and growth seemed to improve (147.5 cm, 2.11 SD at the age of 13 8/12). Menarche occurred at 13 years and her height at 25 years was 150 cm (2.47 SD) indicating that there was no apparent benefit from rGH. With the exception of short stature, further characteristics associated with GLI2 point mutations (for review see [Kevelam et al., 2012]) were not present. In fact, the patient showed scoliosis and several facial dysmorphic features, i.e., a high anterior hairline, a short philtrum, a pointed chin, and a long nose. Esotropia was noted. Cranial MRI showed abnormal temporal myelinization. Psychomotoric development was apparently normal, she is currently unemployed but has a qualification as an office employee. Formal intelligence tests were not performed. Family history showed two abortions (one with twins) of her mother. Clinical data and pictures available from the grandmother and the deceased father did not identify any phenotypic abnormalities. Her father died at the age of 33 from complications of diabetes mellitus. The height of her mother was 161 cm, her father was 173 cm tall (1.16 SD) and thin (60 kg, BMI 20.76). The paternal grandmother was 156 cm tall (2.47 SD), the grandfather 180 cm tall (þ0.28 SD). Grandmaternal weight was (70 kg, BMI 31.11) whereas the father was of normal weight. Due to the severe growth retardation and other minor signs, Silver–Russell syndrome (SRS) was considered but was not probable because of the microcephaly. Indeed, genetic testing for chromosome 11p15 imbalances and methylation defects as well as maternal uniparental disomy of chromosome 7 by MS-MLPA (SALSA Kit ME30, MRC Holland, Amsterdam/NL) and MSSNuPE [Begemann et al., 2012] was negative. The subsequent molecular karyotyping with an Affymetrix GeneChip1GenomeWide Human SNP 6.0-Array showed a heterozygous 4.3 Mb deletion in 2q14.2q14.3 (hg19: chr2:121642461–125977825) (Fig. 1a), including 12 of the 13 exons of the GLI2 and six additional genes. The deletion was confirmed by a qPCR approach. MLPA with the P187-HPE SALSA kit (MRC Holland) confirmed the heterozygous deletion of exons 2–13 of the GLI2 gene, whereas exon 1 was not affected (Fig. 1b). We could exclude the deletion in the patients mother. As the father was already dead we tested DNA samples of the paternal grandparents. The deletion was identified in the paternal grandmother. The work was approved by the Ethical Review board of the University Hospital of the RWTH Aachen, Germany.
DISCUSSION The identification of a 4.3 Mb deletion in 2q14 in a patient and her family without any features of the HPE spectrum confirms the
KORDAß ET AL.
1123
FIG. 1. Identification of the 2q14.2 deletion in the patient presented here. (a) SNP array signal distribution pattern. The figures include the schematic presentation of the copy number segments, gene entries in this region, distribution of markers, and physical positions. (b) Result of the P187-HPE MLPA analysis confirming the heterozygous deletion of the exons 2–13 of GLI2.
incomplete penetrance reported for both point mutation and genomic imbalances affecting GLI2 [Roessler et al., 2003; Kevelam et al., 2012]. However, the family presented here is distinctive as none of the three identified heterozygote family members showed any typical signs of HPE, whereas all patients reported so far were referred for genetic testing because at least one member exhibiting HPE and related features (Table I). Apart from the unspecific feature of growth retardation, the only clinical sign compatible with HPE was the growth hormone deficiency in childhood, but in adulthood, pituitary hormone levels were in the normal range (Table I). However, the significance of the deletion in the patient presented here is uncertain. As the affected chromosomal region includes six other genes, one might assume that one of them influences and modifies the phenotype. Nevertheless, the two other heterozygotes in the family do not show the same phenotype. Indeed, the paternal grandmother is of small stature, whereas the deceased father was thin. The 2q14 deletion in the patient presented here was different in size (4.3 versus 1.3 Mb) and located more proximally than the aberration reported by Kevelam et al. [2012]. As a result, both deletions share only two genes, GLI2 and TFCP2L1. As the patient presented here did not show any signs of heterotaxy, we can confirm the suggestion of Kevelam et al. [2012] that the latter gene is not involved in the etiology of that symptom. For the other genes affected by the deletion in the patient, an association with a specific phenotype has been suggested only for the RNU4ATAC gene. However, the patient described here did not show any clinical signs of microcephalic osteodysplastic primordial dwarfism type I, and a heterozygote effect in this autosomal recessive condition has not yet been reported [Abdel-Salam et al., 2012]. In summary, the patient presented here illustrates the need to identify additional families with GLI2 mutations and to document their phenotypes. In the present patient, the persistent growth
retardation was the key feature leading to molecular testing, and therefore, we suggest that molecular karyotyping should be applied in growth retarded patients with only minor dysmorphic features with or without intellectual disability.
ACKNOWLEDGEMENT We thank the family for participating in this study.
REFERENCES Antich J, Carbonell X, Mas J, Clusellas N. 1983. De novo interstitial deletion of the long arm of chromosome 2 in a malformed newborn with a karyotype 46,XY,del(2)(q12q14). Acta Paediatr Scand 72:631–633. Abdel-Salam GM, Abdel-Hamid MS, Issa M, Magdy A, El-Kotoury A, Amr K. 2012. Expanding the phenotypic and mutational spectrum in microcephalic osteodysplastic primordial dwarfism type I. Am J Med Genet A 158A:1455–1461. Baker KL, Rees MI, Thompson PW, Howell RT, Cole TR, Houghes HE, Upadhyaya M, Ravine D. 2001. Chromosome 2 interstitial deletion (del(2)(q14.1q21)) associated with connective tissue laxity and an attention deficit disorder. J Med Genet 38:493–496. Begemann M, Leisten I, Soellner L, Zerres K, Eggermann T, Spengler S. 2012. Use of multi-locus methylation-specific single nucleotide primer extension (MS-SNuPE) technology in diagnostic testing for human imprinted loci. Epigenetics 7:473–481. Cohen LE. 2012. GLI2 mutations as a cause of hypopituitarism. Pediatr Endocrinol Rev 9:706–709. Davis E, Grafe M, Cunniff C, Jones KL, Bogart M. 1991. Interstitial deletion of chromosome 2q associated with ovarian dysgenesis. Clin Genet 35:386–390. Flemming GM, Klammt J, Ambler G, Bao Y, Blum WF, Cowell C, Donaghue K, Howard N, Kumar A, Sanchez J, Stobbe H, Pfa¨ffle RW.
1124 2013. Functional characterization of a heterozygous GLI2 missense mutation in patients with multiple pituitary hormone deficiency. J Clin Endocrinol Metab 93:E567–E575. Franc¸a MM, Jorge AA, Carvalho LR, Costalonga EF, Vasques GA, Leite CC, Mendonca BB, Arnhold IJ. 2010. Novel heterozygous nonsense GLI2 mutations in patients with hypopituitarism and ectopic posterior pituitary lobe without holoprosencephaly. J Clin Endocrinol Metab 95:E3 84–E391. Franc¸a MM, Jorge AA, Carvalho LR, Costalonga EF, Otto AP, Correa FA, Mendonca BB, Arnhold IJ. 2013. Relatively high frequency of non-synonymous GLI2 variants in patients with congenital hypopituitarism without holoprosencephaly. Clin Endocrinol 78:551– 557. Frydman M, Steinberger J, Shabtai F, Katznelson MB, Varsano I. 1989. Interstitial deletion 2q14q21. Am J Med Genet 34:476–479. Gustavsson P, Schoumans J, Staaf J, Jo¨nsson G, Carlsson F, Kristoffersson U, Borg A. 2006. Hemizygosity for chromosome 2q14.2-q22.1 spanning the GLI2 and PROC genes associated with growth hormone deficiency,
AMERICAN JOURNAL OF MEDICAL GENETICS PART A polydactyly, deep vein thrombosis and urogenital abnormalities. Clin Genet 69:441–443. Kevelam SH, van Harssel JJ, van der Zwaag B, Smeets HJ, Paulussen AD, Lichtenbelt KD. 2012. A patient with a mild holoprosencephaly spectrum phenotype and heterotaxy and a 1.3 Mb deletion encompassing GLI2. Am J Med Genet A 158A:166–173. Lucas J, Faivre J, Le Mee F, Hubert S, Pluquailec K, Picard F. 1987. De novo interstitial deletion of the long arm of chromosome 2: 46,XXX, del(2)(q14q21), associated with premature craniosynostosis. Ann Genet 30:33–38. Peng HH, Wang CJ, Wang TH, Chang SD. 2006. Prenatal diagnosis of de novo interstitial 2q14.2–2q21.3 deletion assisted by array-based comparative genomic hybridization: A case report. J Reprod Med 51:438–442. Roessler E, Du YZ, Mullor JL, Casas E, Allen WP, Gillessen-Kaesbach G, Roeder ER, Ming JE, Ruiz i, Altaba A, Muenke M. 2003. Loss-of-function mutations in the human GLI2 gene are associated with pituitary anomalies and holoprosencephaly-like features. Proc Natl Acad Sci USA 100:13424–13429.
