Conditions Previously Screened

Conditions Previously Screened

Duchenne Muscular Dystrophy (DMD)
  • Screened by Early Check via CK-MM from October 2020 - June 2023
  • Screening for DMD via DNA sequencing started in late 2023

Approximately 90% of babies with Duchenne muscular dystrophy (DMD) can be identified by Early Check using DNA sequencing. It is considered by the Early Check team to be a condition with potential treatments (Group 2). Currently, there is no cure for muscular dystrophy, but there are treatments and early intervention services that can help. 

The muscular dystrophies are a group of rare diseases that cause muscle damage and weakness. DMD is the most common muscular dystrophy that affects children. It is also one of the most severe muscular dystrophies. It causes weakness that gets worse over time and leads to early death, often in adulthood. It happens most often in boys, but girls can sometimes be affected. About 1 in every 5,000 boys has Duchenne. 

The other muscular dystrophies are even less common and can happen in boys or girls. Early Check screening will not find all types of muscular dystrophy. 



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 choose to have testing and genetic counseling to learn whether that risk is high or low, which may be important when planning for more children.

Children with DMD can begin to experience muscle weakness as early as 2 or 3 years of age. This is typically first noticed in the neck, shoulders, upper arms and thighs. This makes 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 are congenital, which can cause symptoms to begin as early as at birth, while other forms begin much later in childhood. 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.

Fragile X Syndrome and Fragile X Premutation
  • Screened by Early Check from 10/15/2018 - 12/10/2021

Although Fragile X Syndrome (FXS) is a rare health condition, it is the most common intellectual disability passed through genes from parents to babies. About 1 in every 4,000 males, and 1 in every 6,000 females has FXS. It causes moderate to severe intellectual challenges and language problems. Children with FXS may also have social and behavioral difficulties. This means they may have problems with attention, impulsive actions, and anxiety. Boys with FXS usually have more severe symptoms than girls. Individuals with FXS typically have normal life spans.



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, early intervention services are available. These support services, like speech, occupational and physical therapy, can help your child learn to walk and talk. Early intervention team members can also help you, as a parent, identify and to address potential common delays associated with 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.

"Early intervention has given us the opportunity to give our son Jack access to therapies, such as occupational therapy and speech therapy, that helped him learn to talk and learn to play with toys. Jack has come a long way, in part due to all the early intervention therapies he received."

– Lisa Thomas, mother of a son with FXS

Spinal Muscular Atrophy (SMA)
  • Screened by Early Check from 10/15/2018 - 3/31/2021
  • Screened by North Carolina newborn screening beginning in early 2021
  • Screening for SMA via DNA sequencing started in late 2023

Most babies with spinal muscular atrophy will now be identified by standard newborn screening and also by Early Check DNA sequencing.

SMA is a genetic condition affecting about 1 in 10,000 new babies in the United States. Over time, muscles of people with SMA get smaller and weaker from poor communication between the spinal cord and muscles. This weakness can be very mild or very severe. People with SMA can begin showing signs and symptoms at different ages, ranging from shortly after birth to adulthood. The condition can lead to death in early childhood or later depending on the type of SMA. Currently, there is no cure for SMA, but there is one approved treatment.



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 approved treatments that target the underlying genetics of SMA. Also, other support services can help with breathing, eating, mobility, palliative care, and other symptoms and challenges.

"There is hope in treating SMA, particularly for children who are diagnosed at or very soon after birth and receive prompt treatment! My family is proof of that."

– Amy Medina, mother of two sons with SMA