Disease characteristics. Townes-Brocks syndrome (TBS) is characterized by the triad of imperforate anus (82%), dysplastic ears (88%) (overfolded superior helices and preauricular tags) frequently associated with sensorineural and/or conductive hearing impairment (65%), and thumb malformations (89%) (triphalangeal thumbs, duplication of the thumb (preaxial polydactyly), and rarely hypoplasia of ...

Cleft hand is an anomaly in which the primary feature is oligodactyly, and it is considered an important congenital malformation. The authors have analyzed the cases they have handled and developed an independent classification based on the number of defective digits. It has been ascertained that the clinical symptoms correlate with the number of defective digits, and a regular pattern was obse...

A locus for triphalangeal thumb, variably associated with pre-axial polydactyly, was previously identified in the zone of polarizing activity regulatory sequence (ZRS), a long range limb-specific enhancer of the Sonic Hedgehog (SHH) gene at human chromosome 7q36.3. Here, we demonstrate that a 295T>C variant in the human ZRS, previously thought to represent a neutral polymorphism, acts as a domi...

Ulnar dimelia (mirror deformity) is a rare dysontogenetic deformity of the upper limb caused by an embryonic disturbance of the developing limb bud. It is characterized by two ulnae, the duplication of the ulnar halves of the carpus, metacarpals and phalanges, with the absence of the radius and thumb. It is commonly unilateral. This anomaly may be associated with shoulder dislocation, fibular d...

A kindred of 15 affected individuals in five generations is described with autosomal dominant inheritance of bilateral five-fingered hand. Some of them had additional pre-axial polydactyly of the fingers or toes and some had partial or complete absence of the tibia. The range of expression of the gene is variable and genetic advice to these families must take account of the whole spectrum of de...

Sanchez Cascos, A. (1972). Archives of Disease in Childhood, 47, 581. Genetics of atrial septal defect. Of 109 cases of atrial septal defect, cases with an isolated defect (92 cases) showed a female preponderance (sex ratio 0 64), but there was a higher risk to the sibs of the male patients, suggesting a multifactorial mechanism. Dermatoglyphs showed a large number of whorls on the fingers. In ...