Can a child get SMA if only one parent is a carrier?

Written by Marisa Wexler, MS | Feb. 1, 2023

Can a child get SMA if only one parent is a carrier?

Category: Causes and Genetics

The five main types of spinal muscular atrophy (SMA) only develop if a person inherits two mutated copies of the SMN1 gene. If only one parent is a carrier, the child can only inherit one mutated copy and it is very unlikely he or she will develop SMA. However, in extremely rare cases, a mutation can develop spontaneously in a sperm or egg cell, so the disease can develop in a child evenif they only inherited one mutated copy from the carrier parent.

About the Author

Marisa Wexler, MS Marisa holds a Master of Science in cellular and molecular pathology from the University of Pittsburgh, where she studied novel genetic drivers of ovarian cancer. Her areas of expertise include cancer biology, immunology, and genetics, and she has worked as a science writing and communications intern for the Genetics Society of America.