Distal Limb Defects and Aplasia Cutis: Adams-Oliver Syndrome.

Adams-Oliver syndrome is a rare congenital condition that should be considered in persons with terminal transverse limb deficiencies and scalp defects (aplasia cutis congenita). Broad phenotypic variability exists in this condition. In its more severe forms, Adams-Oliver syndrome can involve the cardiovascular system, central nervous system, gastrointestinal tract, and genitourinary system and should require prompt evaluation by appropriate subspecialists. Extremity involvement is typically bilateral and asymmetrical, with lower extremities involved more than upper extremities. Brachydactyly is the most common limb defect, and severity ranges from hypoplastic nails to complete absence of the distal limb. The syndrome has been described as resulting from autosomal dominant and recessive modes of inheritance, but most cases are sporadic. No gene has been identified. Although the exact pathogenic mechanism is unknown, a common hypothesis is that a vascular disturbance occurs in watershed areas, such as cranial vertex and limbs, during fetal development.