Laryngeal Abductor Paralysis

Description

Laryngeal abductor paralysis is an autosomal dominant condition characterized by variable penetrance and expressivity ranging from mild symptoms to neonatal asphyxia. (summary by Morelli et al., 1982; Manaligod and Smith, 1998).

Clinical Features

Grundfast and Milmoe (1982) reported congenital bilateral abductor vocal cord paralysis in a father and his son and daughter. The vocal cord paralysis was associated with swallowing difficulty during infancy in all 3. Although both the son and daughter required tracheostomies during the neonatal period, both showed improvement of vocal cord movement during infancy so that decannulation was possible before 14 months of age. Grundfast and Milmoe (1982) suspected delay in neurologic maturation as the cause of the disorder.

Morelli et al. (1980, 1982) described 5 members of a family with autosomal dominant inheritance of Gerhardt syndrome. The severity of the disorder was variable: 2 died of neonatal asphyxia, one had partial paralysis with mild symptoms, and 3 required surgery. Two of those affected had clubfoot.

Cunningham et al. (1985) described a brother and 2 sisters with neonatal stridor due to abductor paralysis. Temporary tracheostomy was necessary in 1. On the mother's side the family history was noncontributory; the father's family history was unavailable.

Schinzel et al. (1990) described a family in which a brother and 2 sisters with remotely consanguineous parents had congenital laryngeal abductor paralysis and moderate mental retardation. In the 2 older sibs, mental deficiency could have resulted from birth asphyxia, but the youngest girl was already microcephalic at birth and had no apparent asphyxia. The mother, who was healthy and of normal intelligence, was found on laryngoscopy to have unilateral laryngeal abductor paralysis.

Manaligod and Smith (1998) reported a family in which 3 members had autosomal dominant inheritance of laryngeal abductor paralysis. Two other family members had hoarseness or a soft voice.

Inheritance

Although X-linked recessive inheritance has been suggested by some pedigrees (see 308850), autosomal dominant inheritance is clear in the kindred reported by Morelli et al. (1980, 1982) which had 5 affected persons in 3 generations with 2 instances of male-to-male transmission, and in the family of Gacek (1976) with father and 2 sons affected.

Brunner and Herrmann (1982) reported an autosomal dominant pedigree with laryngeal abductor and adductor paralysis and suggested linkage to HLA on chromosome 6.

Schinzel et al. (1990) suggested autosomal dominant inheritance of congenital laryngeal abductor paralysis and moderate mental retardation in 3 affected sibs of remotely consanguineous parents; however, autosomal recessive inheritance, with both parents carriers and the mother an affected homozygote, and X-linked inheritance were also considered possible.