Trisomy-12p syndrome: Family study and prenatal diagnosis.
A young unrelated Indian couple produced a baby who had an unusual facies, marked abdominal distension and muscular hypotonia. At 8 weeks cytogenetic investigation revealed what appeared to be trisomy-21. Because this did not agree with the clinical signs the parents were tested and the mother was found to have a balanced translocation between chromosomes 12 and 14; her karyotype was 46,XX,rcp(12; 14)(p11; q11) and it was realized that her son had inherited her translocation chromosome involving the short arms of chromosomes 12 and 14. He thus had trisomy-12p. The present case and 10 others reported in the literature confirm that trisomy-12p produces a recognizable syndrome. Parents carrying a balanced translocation have a 50:50 risk of producing an abnormal infant at every pregnancy because both the trisomic and monosomic conditions may be viable. Amniocentesis for fetal karyotyping must be recommended to the couples concerned.
D002869:Chromosome Aberrations / Q000473:pathology*; D025063:Chromosome Disorders; D002906:Chromosomes, Human, 6-12 and X; D005190:Family; D005260:Female; D005817:Genetic Counseling; D006801:Humans; D007223:Infant; D007621:Karyotyping; D008297:Male; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014314:Trisomy