• Dbf, mouse mutant doublefoot
• PPD, preaxial polydactyly
• SD1, syndactyly type 1
• SHH, sonic hedgehog gene
• Ssq, mouse mutant Sasquatch
• TPT, triphalangeal thumb-polydactyly syndrome

The F form of acropectorovertebral dysgenesis, also called F syndrome, is a rare dominantly inherited fully penetrant skeletal disorder.¹ The name of the syndrome is derived from the first letter of the surname of the family in which it was originally described. Major anomalies include carpal synostoses, malformation of first and second fingers with frequent syndactyly between these digits, hypoplasia and dysgenesis of metatarsal bones with invariable synostosis of the proximal portions of the fourth and fifth metatarsals, variable degrees of duplication of distal portions of preaxial toes, extensive webbing between adjacent toes, prominence of the sternum with variable pectus excavatum and spina bifida occulta of L3 or S1. Affected individuals also have minor craniofacial anomalies and moderate impairment of performance on psychometric tests.³

Two families have been reported to date. The condition was first described by Grosse¹ in eight members of a four generation American family of European origin. Camera⁴ presented an Italian family with two affected relatives and a very similar phenotype, suggesting the diagnosis of F syndrome. Recently, Dundar et al² reported a six generation Turkish family with an acropectoral-like condition showing some phenotypic overlap with F syndrome. Affected individuals have soft tissue syndactyly of all fingers and toes and, to a variable degree, pre-axial polydactyly of hands and feet. The condition was mapped to chromosome region 7q36.

Here we report that the F syndrome family originally described by Grosse et al¹ maps to chromosome region 2q36 and is thus distinct from the acropectoral syndrome published by Dundar et al.²