The following information may help to address your question:
How is spondylothoracic dysostosis inherited?
Spondylothoracic dysostosis is
inherited in an
autosomal recessive fashion. This means that to be affected, a person must have a
mutation in both copies of the responsible
gene in each
cell. Affected people inherit one mutated copy of the gene from each parent, who is referred to as a
carrier. Carriers of an autosomal recessive condition typically do not have any signs or symptoms (they are unaffected).
[1]
Last updated: 3/29/2017
What is spondylothoracic dysostosis?
Spondylothoracic dysostosis (STD) is a rare condition that affects the bones of the spine and the ribs.
[2] The term “Jarcho-Levin
syndrome” in many cases is used as a synonym for STD, and sometimes as a synonym for another condition known as
spondylocostal dysostosis, which has several common features with STD. Also, the term “Jarcho-Levin syndrome” is often used for all radiologic features that include defects of the
vertebrae and abnormal rib alignment.
[3] Signs and symptoms of STD are generally present at birth and may include short-trunk dwarfism (a short body with normal length arms and legs); a small chest cavity; misshapen and abnormally-fused vertebrae (bones of the spine); and fused ribs at the part nearest the spine. Affected people may also have life-threatening breathing problems and recurrent lung infections, which can significantly reduce lifespan. It can occur in any population; however, it occurs most frequently in people of Puerto Rican ancestry.
[1] It is caused by changes (
mutations) in the
MESP2 gene and is inherited in an
autosomal recessive manner.
[2][1][4] Treatment is based on the signs and symptoms present and may include surgery for bone malformations and respiratory support.
[4]
Last updated: 3/29/2017
What are the signs and symptoms of spondylothoracic dysostosis?
Signs and symptoms of spondylothoracic dysostosis include spine and vertebral abnormalities, which result in a shortened spine, neck, and trunk, as well as rib anomalies including fused ribs. This combination of features result in a "crab-like" appearance to the rib cage. Although the neck and midsection of individuals with spondylothoracic dysostosis are shortened, the arms and legs grow normally. As such, individuals with spondylothoracic dysostosis have
short stature and are said to have short-trunk dwarfism.
[1][2]
The spine and rib abnormalities may cause other complications. Infants with this condition are born with a small chest that cannot expand appropriately. This often leads to life-threatening breathing problems. As the lungs expand, the narrow chest forces the muscle that separates the abdomen from the chest cavity (the diaphragm) down and the abdomen is pushed out. The increased pressure in the abdomen can cause a soft out-pouching around the lower abdomen (inguinal
hernia) or belly-button (umbilical hernia).
[2]
Most individuals with spondylothoracic dysostosis have normal intelligence and neurological problems are infrequent.
[5]
Symptom severity may vary from patient to patient with spondylothoracic dysostosis; however, symptoms tend to be the worse for individuals who carry two E230X
mutations in the
MESP2 gene.
[1]
Last updated: 3/29/2017
How might spondylothoracic dysostosis be treated?
There is no cure for spondylothoracic dysostosis. Treatment usually consists of intensive medical care, including early and aggressive treatment of respiratory infections,
physical therapy, bone surgery, and orthopedic treatment.
[6][7] Surgery may then be needed for chest wall or spine deformities, such as severe
scoliosis. An e
xternal bracing, for example, by use of an expandable prosthetic titanium rib may be used for some cases.[3]
Last updated: 3/29/2017
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Last updated: 12/6/2017
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