The muscular dystrophies are genetic conditions that cause damage to muscles cells that cannot be repaired as happens in healthy people. This means that muscles continue to get weaker over time. Some muscular dystrophies cause severe weakness in muscles of the heart, usually causing death in early adulthood. Other muscular dystrophies cause milder weakness and result in a normal lifespan.

The most common muscular dystrophy is Duchenne (DMD). It is caused by a variation in the DMD gene. In a healthy person, this gene provides the instructions for an important protein called dystrophin that protects the muscle fibers from damage. Variations in the DMD gene lead to a lack of dystrophin and muscle damage that cannot be repaired.

Parents of a child with muscular dystrophy have an increased risk for having future children with the same condition. Parents can have testing and genetic counseling to learn whether that risk is high or low, which is important when planning for more children.

Children with Duchenne (DMD) can begin to experience muscle weakness as early as age 2 or 3 years of age. This is typically first noticed in the neck, shoulders, upper arms and thighs, making it difficult to run, climb stairs, lift the arms, and stand up from sitting on the floor. Balance can also be affected.

More rare childhood muscular dystrophies can cause symptoms to begin as early as at birth for the congenital muscular dystrophies or much later in childhood for other forms. Symptoms can range from mild to severe.

There is currently no cure for the muscular dystrophies, but early intervention, medication, and promising new treatments can help. Early treatment can reduce muscle damage and help to preserve strength. For some, targeted gene therapy may slow the progression of the disease.

Learn more about muscular dystrophy, support and information for families, and promising research at the Muscular Dystrophy Association.

FXS is a genetic condition caused by changes in a gene that is on the X chromosome. This gene is called the FMR1. Everyone has this FMR1 gene on their X chromosome. Women have two X chromosomes, so they have two copies of this gene. Men have one X chromosome and one Y chromosome, so they have only one copy of the gene.

The FMR1 gene usually makes a protein that is needed for normal brain development. People who have FXS do not make this protein. Women often have milder symptoms than men because they have two X chromosomes. While one of their X chromosomes may not be producing the healthy FMR1 protein, the other one is.

A child with FXS might have learning disabilities or developmental delays in walking and talking. They might also experience anxiety, hyperactivity, and a short attention span. Some children with FXS also have autism. Physically, they may have an elongated face, large ears, and loose connective tissue, which can result in ear infections, hernias, and loose joints.

There is no cure for FXS, but if your child has the condition, you can begin early support services. These services can help your child learn to walk and talk. They can also help you, as a parent, prepare to address characteristics of FXS in your child, such as difficulties processing tastes and smells. There are doctors who work specifically with people who have FXS to develop the best treatment plan.

• Introduction to Fragile X (National Fragile X Foundation)
• Receiving a New Diagnosis (National Fragile X Foundation)

SMA is a genetic condition that robs people of physical strength by affecting the motor nerve cells in the spinal cord. This can take away their ability to walk, eat, or breathe. It's the number one genetic cause of death for infants.

SMA is caused by a variation in a gene in the survival motor neuron gene 1 (SMN1). In a healthy person, this gene manages nerves that control our muscles. Without it, those nerve cells can’t properly function and eventually die, leading to debilitating muscle weakness. About 1 in every 50 Americans is a genetic carrier of SMA, which can affect any race or gender.

People with SMA have difficulty performing the basic functions of life, like breathing and swallowing. However, SMA does not affect a person’s ability to think, learn, and build relationships with others.

For now, there is no cure for SMA, but there’s great reason for hope. Thanks to the dedication of the SMA community and the hard work of researchers, there is now Spinraza, the first-ever approved treatment that targets the underlying genetics of SMA. Also, other support services can help with breathing, eating, mobility, palliative care, and other symptoms and challenges.

• Living with SMA (Cure SMA)
• Fact Sheet on SMA in North Carolina (Cure SMA)
• Fact Sheet on Screening for SMA (Cure SMA)