Objective: To describe a mother who had autopsy-proved amyotrophic lateral sclerosis and her daughter who had clinically diagnosed Creutzfeldt-Jakob disease.
Design: Case reports with molecular genetic analyses.
Setting: A tertiary care center.
Patients: The mother had progressive upper and lower motor neuron symptoms and signs starting at the age of 54 years. Electrophysiological testing supported the diagnosis of amyotrophic lateral sclerosis. Autopsy results confirmed the diagnosis. Her daughter had received injections of human growth hormone prepared from pooled human pituitary glands as a child. At the age of 31 years, she experienced the onset of gait ataxia and dysarthria. Cerebrospinal fluid showed the 14-3-3 protein. Cognitive difficulties ensued. She progressed to a nearly akinetic and mute state. She had overt visible fasciculations and muscle atrophy in the legs.
Main outcome measures and results: Neither patient carried a mutation in the prion protein gene. Both were homozygous for methionine at the polymorphic codon 129. Neither patient carried a deletion of the 5 exons of the superoxide dismutase 1 gene.
Conclusions: It is uncertain whether the 2 cases occurred in the same family by chance or whether the patients shared genetic risk factors for the 2 diseases. The possibility that homozygosity at codon 129 is a risk factor for amyotrophic lateral sclerosis is being tested in a case-control study.