X-Linked Immunoneurologic Disorder

X-linked immunoneurologic disorder is characterized by immune deficiency and neurological disorders in females, and by neonatal death in males.

Epidemiology

The syndrome has been described in only one family with nine affected individuals (five males and four females) spanning two generations.

Clinical description

Symptomatic females present slowly progressive proximal muscle weakness, leg hyperreflexia, pes cavus, increased muscle tone in the legs, poor bladder function, static reduced night vision, and frequent sinopulmonary infections associated with IgG2 deficiency. Males present with low birth weight and severe hypotonia that leads to death in the neonatal period.

Etiology

The gene locus has been mapped to Xq26-qter.

Differential diagnosis

The syndrome should be considered in the differential diagnosis of hereditary spastic paraplegia in females and of other causes of severe neonatal hypotonia in males.

Genetic counseling

The condition is thought to be transmitted in an X-linked dominant manner.