Terminal 2q deletion and partial trisomy chromosome 15q: a clinical and cytogenetic study.

Summary: Terminal 2q deletion and partial trisomy chromosome 15q: a clinical and cytogenetic study: We report on a 5 years old female patient with a karyotype 46, XX, add (2), t(2; 15) (q37;q22) associated with dysmorphic facial features, digital deformities, heart defect (mild mitral regurge) and severe mental retardation. This is the third reported case worldwide on the terminal 2q deletion and trisomy of chromosome 15q syndrome. The findings in this case and our literature review, delineates the pattern of malformations secondary to trisomy of 15q and deletion of 2q.Key words: Trisomy chromosome 15q - Deletion 2q - Mental retardation - Facial dysmorphism.INTRODUCTIONTrisomy of the distal part of chromosome 15q is an extremely rare chromosomal disorder, characterized by prenatal and postnatal overgrowth, mental retardation, and craniofacial malformations (10, 19). Additional abnormalities include short neck and skeletal malformations in the fingers and toes with scoliosis and cardiac defects may occur in some cases (2) and rarely renal anomalies in the form of renal agenesis, horseshoe kidney, and hydronephrosis were described (20). To date, about 41 patients with trisomy or tetrasomy for distal 15q have been reported (4). The range and severity of symptoms and physical findings vary from case to case, depending upon the length and location of the duplicated portion of chromosome 15q (9), most of the reported cases have resulted from unbalanced translocations or deletions involving chromosome 15 and another chromosome as well as other structural chromosomal abnormalities (17).Deletions of 2q, 12p, 13q, and 20p have been described in association with trisomy 15q (3, 5, 7,13). To date, only two cases with partial duplication of 15q and deletion of 2q have been reported (7, 21). The 2q37 locus is one of the most commonly deleted subtelomeric regions, it is known as '2q37-deletion syndrome'; brachydactyly-men- tal retardation syndrome or Albright's hereditary osteodystrophy-like syndrome (OM1M 600430) (14). Patients present with intellectual deficiency, facial dysmorphism and brachydactyly, associated with behavioral problems, short stature, autism or autism spectrum disorders of varying severity and overweight or obesity (12). The study of duplication or deficiency of chromosomes in affected individuals can offer insight into the delineation of segmental aneuploidy syndromes. In this study we report a case with unbalanced chromosomal rearrangement of distal 15q and terminal del of 2q37.CLINICAL REPORTA five-year-old female with delayed motor milestones of development was referred to the Department of Clinical Genetics, National Research Center, Egypt. She was the offspring of a healthy non-consanguineous 23 and 32-year-old mother and father, respectively. The pregnancy and delivery histories were unremarkable except for intrauterine growth retardation and low birth weight. The patient's weight, height and head circumference were 13.3 Kg (-1.88 SD), 110 cm (+0.3 SD) and 48.7 cm (- 1.6 SD) respectively. She had a plageocephalic skull and dysmorphic facies; long face, prominent metopic suture, arched eyebrows with sparse hair at the outer third, narrow palpebral fissure, epicanthal fold, broad and prominent nasal bridge, hypoplastic ala nasi, long flat philtrum, thin upper lips, posteriorly rotated low set ears with prominent columella and pointed chin (Fig. 1 a, b). She had a skin appendage on the chest and low displaced hypoplastic nipples (Fig lc, d). The hands were narrow and long with abnormal dermatoglyphics, hypoplastic palmar crease, camptodactyly of 2nd- 3rd and 4th fingers, tapering fingers and soft tissue syndactyly between 2nd, 3rd, 4th & 5th fingers (Fig. le, f). X-rays of the hand showed soft tissue syndactyly between 2nd, 3rd, 4th and 5th fingers (Fig. lg). There were also camptodactly of 2nd and 3rd toes, overriding between 2nd, 3rd, 4lh and 5th toes, lateral deviation of toes, flat feet and talipus equino vulgum corrected by a splint (Fig. …