Muscular dystrophy (MD) is a group of genetic diseases that affect about 16 to 25 per 100,000 people in the US, with the most common childhood form being Duchenne muscular dystrophy (DMD) and the most common adult form being myotonic dystrophy. The prevalence of DMD is estimated at around 1 in 3,500 live male births. Prenatal carrier screening for this is part of the ACMG Tier 3 expanded carrier panel. This is different from spinal muscular atrophy (SMA). As we recently had a patient who was a MD carrier, with affected male children, who we cared for, we decided to do a quick review of muscular dystrophy: its prevalence, genetics, and evaluation of asymptomatic maternal carriers.1. https://www.mda.org/disease/duchenne-muscular-dystrophy/causes-inheritance2.https://www.nichd.nih.gov/health/topics/musculardys/conditioninfo/causes3. https://www.nhs.uk/conditions/muscular-dystrophy/4. ACMG: https://thednaexchange.com/2022/03/30/acmg-carrier-screening-guideline-the-hypothetical-tier-3-panel/#:~:text=The%20goal%20of%20this%20ACMG,1%20in%2040%2C000%20or%20higher.