Congenital cerebellar hypoplasia and hypogonadotropic hypogonadism.

The association of cerebellar ataxia and non-neurological syndromes is a well known phenomenon. A 20-year-old male patient presented with a longstanding and non-progressive ataxia. Magnetic resonance examination revealed marked inferior vermian-cerebellar hypoplasia. He also showed a hypogonadism with low serum gonadotropin and prolactin levels. Chronic pulsatile gonadotropin-releasing hormone (GnRH) administration resulted in a small non-pulsatile luteinizing hormone (LH) increase and no follicle-stimulating hormone (FSH) elevation. This hormonal pattern suggests a primary deficiency of the gonadotroph and lactotroph cells, rather than a hypothalamic lesion. This is the first report where cerebellar hypoplasia of congenital origin is associated with hypogonadotropic hypogonadism. Because of consanguinity, autosomal recessive transmission is considered.