Marshall-Smith syndrome (MRSHSS)

What is Marshall-Smith syndrome (MRSHSS)?

This rare disease affects multiple parts of the body.

The main symptoms of the syndrome are advanced bone age, a failure to thrive (a difficulty in gaining weight), characteristic facial features and intellectual disability.

What gene changes cause Marshall-Smith syndrome (MRSHSS)?

Gene changes in the NFIX gene are responsible for the syndrome.

For now most cases of the syndrome are the result of a de novo or new mutation, making each case the first in a family.

In some cases, a genetic syndrome may be the result of a de-novo mutation and the first case in a family. In this case, this is a new gene mutation which occurs during the reproductive process.

What are the main symptoms of Marshall-Smith syndrome (MRSHSS)?

The main symptoms of the syndrome are intellectual disability and developmental delay. This is usually accompanied by very severe breathing issues.

The unique facial features associated with the syndrome include a prominent forehead, widely spaced eyes that may also protrude, depressed nasal bridge, a small nose and a small jaw. A blue tint to the white of the eyes may also be present in affected individuals. Excessive hair growth has also been identified as a symptom of the syndrome.

Advanced bone age is another feature of the disease, along with a failure to thrive and to gain weight. Scoliosis, a curving of the spine, is also common.

Other medical issues related to the syndrome include heart defects (particularly septal defects), an umbilical hernia and hearing loss.

How does someone get tested for Marshall-Smith syndrome (MRSHSS)?

The initial testing for Marshall-Smith syndrome can begin with facial analysis screening, through the FDNA Telehealth telegenetics platform, which can identify the key markers of the syndrome and outline the need for further testing. A consultation with a genetic counselor and then a geneticist will follow.

Based on this clinical consultation with a geneticist, the different options for genetic testing will be shared and consent will be sought for further testing.

Get Faster and More Accurate Genetic Diagnosis!

More than 250,000 patients successfully analyzed!
Don't wait years for a diagnosis. Act now and save valuable time.

Start Here!

"Our road to a rare disease diagnosis was a 5-year journey that I can only describe as trying to take a road trip with no map. We didn’t know our starting point. We didn’t know our destination. Now we have hope."


Paula and Bobby
Parents of Lillie

What is FDNA Telehealth?

FDNA Telehealth is a leading digital health company that provides faster access to accurate genetic analysis.

With a hospital technology recommended by leading geneticists, our unique platform connects patients with genetic experts to answer their most pressing questions and clarify any concerns they may have about their symptoms.

Benefits of FDNA Telehealth


Our platform is currently used by over 70% of geneticists and has been used to diagnose over 250,000 patients worldwide.


FDNA Telehealth provides facial analysis and screening in minutes, followed by fast access to genetic counselors and geneticists.

Ease of Use

Our seamless process begins with an initial online diagnosis by a genetic counselor and follows by consultations with geneticists and genetic testing.

Accuracy & Precision

Advanced artificial intelligence (AI) capabilities and technology with a 90% accuracy rate for a more accurate genetic analysis.

Value for

Faster access to genetic counselors, geneticists, genetic testing, and a diagnosis. As fast as within 24 hours if required. Save time and money.

Privacy & Security

We guarantee the utmost protection of all images and patient information. Your data is always safe, secure, and encrypted.

FDNA Telehealth can bring you closer to a diagnosis.
Schedule an online genetic counseling meeting within 72 hours!