Duplication of the segment q12.2 leads to qter of chromosome 22 due to paternal inversion 22(p13q12.2).

A 1730-g male infant, born at 37 weeks gestation, had multiple congenital anomalies, consisting of microcephaly, hypertelorism, bilateral cleft lip and palate, micrognathia, low-set ears, and cryptorchidism. Chromosome analysis showed a recombinant 22 derived from the paternal inversion (22)(p13q12.2). The proband's karyotype is 46,XY,rec(22),dup q,inv(22)(p13q12.2)pat, which has a duplication of q12.2 leads to qter. An identical recombinant has been reported in a female infant in Mexico whose mother was a carrier of the inversion. Similar congenital anomalies present in these two patients demonstrate the phenotype of duplication of the distal long arm 22. This report also documents the occurrence of an identical inversion in two apparently unrelated Mexican families.