Clinical Genetics 1979: 15: 541-542
Letters to the Editors Partial trisomy 1q due to tandem duplication Key words: Partial trisomy lq; tandem duplication.
Sirs, Rehder & Friedrich (1979) recently described partial trisomy l q syndrome and summarized the characteristic symptoms. These observations may be supplemented by the case of a boy (now aged 9 months) in whom similar clinical features enabled us to identify a de novo elongation of the long arm of chromosome 1 as tandem duplication. The boy is the second child of healthy, 21-year-old parents. He was born by breech delivery after 37 weeks of gestation. His
birth weight was 2310 g, and his length 46 cm. Growth and development were delayed. Physical examination at the age of 6 weeks revealed a hydrocephalic configuration of the skull with large fontanelles and a wide open sagittal suture, a prominent forehead and a small triangular face with a small, pointed chin. There was mid-facial hypoplasia, deeply set eyes, upward slanting of the palpebral fissures and biepharophimosis. The bridge of the nose was depressed, the nose was beaked a t the tip with a long nasal septum and anteverted nostrils. The
Fig. 1. Propositus at the age of 6 weeks.
OOO9-9163/79/060541-02$02.50/0 0 1979 Munksgaard, Copenhagen
542
FLAT2 A N D FONATSCH
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Fig. 2. Chromosome 1 pairs from three different metaphases. The chromosome on the left side of each pair displays duplication of band region l q 3 2 lq44
p h i h u m was long and prominent, and the mouth was carp-like. The ears were low set and posteriorly rotated. Furthermore, the child displayed a short neck, widely spaced nipples, small umbilical hernia, hypospadias and right kryptorchidism, as well as clinodactyly of both 5th fingers, distally placed triradii, 8 whorls and 2 ulnar loops on the finger tips. A heart defect could not be ascertained, but electrocardiography showed left ventricular enlargement. Hydrocephaly was not confirmed. Surgical intervention had been necessary because of bilateral hydronephrosis due to ureteral stenoses. (Some of the clinical features can be seen in Fig. 1.) Cytogenetic investigation revealed a karyotype with an elongated long arm of one of the chromosomes 1. Both parents had a normal karyotype. Giemsa banding patterns suggested duplication of the band region lq32 -+ lq44 (Fig. 2). The karyotype designation is thus 46,XY, dir dup (lq) (q32 --t q44). Tandem duplication lq32 -+ lq44, lead-
ing to partial trisomy Iq has been described previously by Steffensen et al. (1977). In their case, as in ours, the clinical features are solely due to the l q triplication and are not influenced by accompanying monosomy, as might be the case in partial trisomy l q due to unbalanced translocation (Rehder & Friedrich 1979). Sibylle Flatz, M. D. Christa Fonatsch, Ph. D.
References Rehder, H. & U. Friedrich (1979). Partial trisomy lq. Clin. Genet. 15, 534-540. Steffensen, D. M., E. H. Y.Chu, D. P. Speert, P. M. Wall, K. Meilinger & R. P. Kelch (1977). Partial trisomy of the long arm of human chromosome 1 as demonstrated by in situ hybridization with 5s ribosomal RNA. Hum. Genet. 36, 25-33.
Address: lnsritut fur Genetik Medizinische Hochschule Hannover P . 0 .Box 610180 0-3000Hannover 61 F. D. R .
Letters to the Editors Partial trisomy 1q due to tandem duplication Key words: Partial trisomy lq; tandem duplication.
Sirs, Rehder & Friedrich (1979) recently described partial trisomy l q syndrome and summarized the characteristic symptoms. These observations may be supplemented by the case of a boy (now aged 9 months) in whom similar clinical features enabled us to identify a de novo elongation of the long arm of chromosome 1 as tandem duplication. The boy is the second child of healthy, 21-year-old parents. He was born by breech delivery after 37 weeks of gestation. His
birth weight was 2310 g, and his length 46 cm. Growth and development were delayed. Physical examination at the age of 6 weeks revealed a hydrocephalic configuration of the skull with large fontanelles and a wide open sagittal suture, a prominent forehead and a small triangular face with a small, pointed chin. There was mid-facial hypoplasia, deeply set eyes, upward slanting of the palpebral fissures and biepharophimosis. The bridge of the nose was depressed, the nose was beaked a t the tip with a long nasal septum and anteverted nostrils. The
Fig. 1. Propositus at the age of 6 weeks.
OOO9-9163/79/060541-02$02.50/0 0 1979 Munksgaard, Copenhagen
542
FLAT2 A N D FONATSCH
-.
Fig. 2. Chromosome 1 pairs from three different metaphases. The chromosome on the left side of each pair displays duplication of band region l q 3 2 lq44
p h i h u m was long and prominent, and the mouth was carp-like. The ears were low set and posteriorly rotated. Furthermore, the child displayed a short neck, widely spaced nipples, small umbilical hernia, hypospadias and right kryptorchidism, as well as clinodactyly of both 5th fingers, distally placed triradii, 8 whorls and 2 ulnar loops on the finger tips. A heart defect could not be ascertained, but electrocardiography showed left ventricular enlargement. Hydrocephaly was not confirmed. Surgical intervention had been necessary because of bilateral hydronephrosis due to ureteral stenoses. (Some of the clinical features can be seen in Fig. 1.) Cytogenetic investigation revealed a karyotype with an elongated long arm of one of the chromosomes 1. Both parents had a normal karyotype. Giemsa banding patterns suggested duplication of the band region lq32 -+ lq44 (Fig. 2). The karyotype designation is thus 46,XY, dir dup (lq) (q32 --t q44). Tandem duplication lq32 -+ lq44, lead-
ing to partial trisomy Iq has been described previously by Steffensen et al. (1977). In their case, as in ours, the clinical features are solely due to the l q triplication and are not influenced by accompanying monosomy, as might be the case in partial trisomy l q due to unbalanced translocation (Rehder & Friedrich 1979). Sibylle Flatz, M. D. Christa Fonatsch, Ph. D.
References Rehder, H. & U. Friedrich (1979). Partial trisomy lq. Clin. Genet. 15, 534-540. Steffensen, D. M., E. H. Y.Chu, D. P. Speert, P. M. Wall, K. Meilinger & R. P. Kelch (1977). Partial trisomy of the long arm of human chromosome 1 as demonstrated by in situ hybridization with 5s ribosomal RNA. Hum. Genet. 36, 25-33.
Address: lnsritut fur Genetik Medizinische Hochschule Hannover P . 0 .Box 610180 0-3000Hannover 61 F. D. R .
