Acropectoral Syndrome

Clinical Features

Dundar et al. (2001) reported a 6-generation Turkish family with a combination of distal limb and sternal abnormalities, inherited in an autosomal dominant fashion. All 22 affected subjects manifested soft tissue syndactyly of all fingers and toes, and preaxial polydactyly was present in 14 affected individuals. A prominent upper sternum and/or a blind-ending inverted U-shaped sinus in the chest wall was also present in 14 cases. Dundar et al. (2001) pointed out the similarity between this phenotype and acropectorovertebral dysplasia (F syndrome; 102510) but noted that in this syndrome the carpal, tarsal, and metatarsal synostoses and vertebral anomalies present in F syndrome were not seen. In addition, the soft tissue syndactyly was more marked than that seen in F syndrome, and the preaxial polydactyly occurred in the feet as well as in the hands.

Prashanth et al. (2012) reported features suggestive of acropectoral syndrome in members of a nonconsanguineous family from southern India. The 13-year-old proposita had pectus carinatum, moderate mental retardation, and preaxial polydactyly on one hand and bifid thumb on the other. Her brother, who had died of traumatic head injury at age 2, reportedly had similar features. The deceased maternal grandfather reportedly had similar defects of the hands and upper chest. The lower limbs of all of those affected were normal.

Mapping

Dundar et al. (2001) demonstrated that the phenotype in the Turkish family is linked to a 6.4-cM region of 7q36 flanked by the EN2 gene (131310) and the marker D7S2423. Dundar et al. (2001) noted that preaxial polydactyly type II (174500) and type III (174600), and triphalangeal thumb-polysyndactyly (see 174500), have been mapped to 7q36. The haplotype in the affected individuals reported by Dundar et al. (2001) is different from those found in the related phenotypes.