SPANX-B and SPANX-C (Xq27 region) gene dosage analysis in Down’s syndrome subjects with undescended testes

Down’s syndrome (DS) is one of the most common numer- ical chromosomal aberrations, usually caused by trisomy of chromosome 21, and is frequently complicated with congen- ital heart defects, duodenal obs truction and other conditions including undescended testis (UDT) (Fonkalsrud 1970). The incidence of undescended testes in DS was reported to be 6.52% (Chew and Hutson 2004) while the incidence of UDT in the first year is approximately 0.2%–0.8% in the nor- mal population (Benson et al . 1991; Ichiyanagi et al . 1998). Rapley et al . (2000) provided evidence for a testicular germ- cell tumours (TGCT) predisposition locus at Xq27; the au- thors obtained an hlod score of 4.7 from families wit…