Diastasis Recti And Weakness Of The Linea Alba

Clinical Features

Chan and Bird (2004) reported a family with abdominal wall muscular hypoplasia as an isolated defect and not associated with the urethral obstruction sequence known as prune belly syndrome (100100). The proband was a 3-year-old boy who presented with abdominal wall laxity and severe constipation. His mother, maternal grandmother, and younger brother had varying degrees of abdominal wall muscular deficiency and constipation. His mother's condition was aggravated by her 2 pregnancies. None of the individuals had evidence of urinary tract or renal pathology, and the muscle deficiency was limited to the abdominal wall. The transmission pattern was consistent with autosomal dominant inheritance. Chan and Bird (2004) postulated that expression in the sons would remain incomplete because abdominal distention due to pregnancy would not occur.

Digilio et al. (2008) reported autosomal dominant transmission of hypoplasia of the abdominal wall muscles with weakness of the linea alba and diastasis recti. A mother, son, and maternal grandmother were affected. All affected patients showed anterior abdominal deficiency without associated dysmorphic features or internal malformations. Echocardiography and abdominal ultrasonography were normal, and urethral obstruction sequence was excluded by urethral cystography, distinguishing the disorder from prune belly syndrome. Digilio et al. (2008) noted the similarities to the family reported by Chan and Bird (2004).

Inheritance

The pattern of transmission of the disorder in the families reported by Chan and Bird (2004) and Digilio et al. (2008) suggests autosomal dominant inheritance.