How is Bethlem myopathy inherited?
Bethlem myopathy is usually inherited in an autosomal dominant pattern. We have two copies of the genes that cause Bethlem myopathy; one from our mother and one from our father. Autosomal dominant inheritance means that if an individual has a genetic change in one copy of the gene that is enough to show symptoms and have the condition. For individuals who have autosomal dominant Bethlem myopathy, there would be a 50% chance to have a child with Bethlem myopathy in each pregnancy.
Sometimes, Bethlem myopathy can be inherited in an autosomal recessive pattern. Autosomal recessive inheritance means that an individual must have a genetic change in both copies of the gene in order to have the condition. Their parents would only have one genetic change and have not been reported to have symptoms. For these families, the unaffected parents would be called carriers. When two parents are carriers for autosomal recessive Bethlem myopathy, there is a 25% chance to have a child with Bethlem myopathy in each pregnancy.
SOURCE: Emory University - Department of Human Genetics in collaboration with ThinkGenetic • https://www.thinkgenetic.com/diseases/bethlem-myopathy-109941/inheritance/67029 • DATE UPDATED: 2019-02-22
Lampe AK, Flanigan KM, Bushby KM, et al. Collagen Type VI-Related Disorders. 2004 Jun 25 [Updated 2012 Aug 9]. In: Adam MP, Ardinger HH, Pagon RA, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2019.Available from: https://www.ncbi.nlm.nih.gov/books/NBK1503/
Genetics home reference, Collagen VI-related myopathy, https://ghr.nlm.nih.gov/condition/collagen-vi-related-myopathy Accessed 21FEB19