What Your Test Results Mean:

Carriers typically show no symptoms of Gracile syndrome; however, carriers are at an increased risk of having a child with Gracile syndrome. Risk for the current or future pregnancies is dependent on your partner’s carrier status. Carrier testing of your partner is recommended in addition to consultation with a genetic counselor for more detailed risk assessment.

Disease Explained:

Gracile syndrome is an inherited condition that affects the ability of the mitochondria to convert energy from food into energy that is useful for the body. The BCS1L protein is part of an enzyme complex called Complex III that is required for the conversion process, and the complex breaks down very quickly when there is a pathogenic variant in the BCS1L gene, resulting in decreased cellular energy and organ damage. Gracile is an acronym for the symptoms of the disease: affected individuals have fetal growth restriction, aminoaciduria (abnormal presence of amino acids in the urine), cholestasis (impeded flow of bile from the liver), iron overload, lactacidosis (lactic acid build-up in the bloodstream), and early death. Individuals with Gracile syndrome typically do not survive beyond the first year of life.

How the Genetics Works:

Gracile syndrome is an autosomal recessive disorder caused by pathogenic variants in the BCS1L gene. In general, individuals have two copies of the BCS1L gene. Carriers of Gracile syndrome have a single variant in one copy of the BCS1L gene while individuals with Gracile syndrome have variants in both copies of their genes, one inherited from each parent. Risk for two carriers to have a child with Gracile syndrome is 25%.