Amish Lethal Microcephaly

A very rare syndrome characterized by extreme microcephaly and early death, within the first year.

Epidemiology

It has been described only in the Old Order Amish of Lancaster County Pennsylvania. In this population, birth prevalence is about 1/500.

Clinical description

Microcephaly is a microcephalia vera (MV), evident at birth or through 22-week fetal ultrasound. Affected children have high urinary levels of alpha-ketoglutaric acid.

Etiology

All affected infants are homozygous for the same mutation of the SLC25A19 gene on chromosome 17 (17q25.3).

Genetic counseling

The condition follows an autosomal recessive pattern of inheritance.

Prognosis

Prognosis is very poor: the average life span of affected infants is between five and six months.