A Case of 3p Partial Trisomy

ABSTRACT

3p partial trisomy is a rare chromosomal anomaly. We experienced a case of 3p partial trisomy in a male neonate. It was diagnosed by clinical and chromosoaml study. He had multiple anomalies such as brachycephaly, wide open fontanelle, square face, hypertelorism, mongoloid palpebral fissure, micrognathia, low set malformed ear, bilateral cleft lip and palate, double outlet right ventricle, atrial septal defect, ventricular septal defect, left ventricular hypoplasia, renal microcysts and micropenis. He was manifested intrauterine growth retardation. Peripheral blood chromosome studies showed an additional chromosomal material at the distal part of the short arm of chromosome 7. Analysis of chromosomes of family members showed that the father had normal karyotype, but the mother had reciprocal balanced translocation,46, XX, t(3;7)(p25;p22). The karyotype formula of the propositus was thus,46,XY,der(7),t(3;7)(p25;p22)mat, that is unbalanced for a duplication 3p25-->3pter, resulting from segregation of a balanced maternal translocation. Two years after patient's birth, his sister was born at 40 weeks of gestation without congenital anomalies. In the case of his sister, amniocentesis and chromosome studies had been done at 16 weeks of gestation. The result of the chromosome analysis was 46,XX,t(3;7)(p25;p22), as in her mother. We report a neonate with multiple congenital anomalies due to partial trisomy for the short arm of chromosome 3, his mother and a female sibling with t(3;7)(p25-->p22).