TRISOMIA 9P DA TRASLOCAZIONE PATERNA T(6;9)(q27;p13)

Since the original description of Rethore in 1970, about 50 cases of trisomy of the short arm (p) of chromosome No. 9 have been reported. The common clinical features include mental retardation, short stature, microcephaly of brachicephalic type, deep set eyes, globular prominent nose, protuberant simple ears, downward slanting of mouth corners, full lips, anomalies of fingers and toes, single palmar crease and unusual dermatoglyphics. These clinical findings are sufficiently distinctive and characteristic to establish trisomy 9p as a new recognizable chromosomal syndrome in which diagnosis may be suspected on clinical grounds before karyotype confirmation. The syndrome may prove to be one of the most common clinical autosomal anomalies in humans, exceeded only by trisomy 21 (Down's syndrome), and 18 (multiple congenital malformation). The present paper describes a 11 yr old female who has the clinical features of this syndrome and is trisomic for part of the short arm of chromosome 9, as the result of a balanced paternal translocation t(6;9) (q21;p13). The cytogenetic and clinical findings of the 52 previously reported cases are briefly reviewed.