Spondylocostal dysostosis, also known as Jarcho-Levin syndrome (JLS), is a rare, heritable

axial skeleton The axial skeleton is the part of the skeleton that consists of the bones of the head and trunk (anatomy), trunk of a vertebrate. In the human skeleton, it consists of 80 bones and is composed of six parts; the human skull, skull (22 bones), als ...

growth disorder. It is characterized by widespread and sometimes severe malformations of the

vertebral column The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral column is the defining characteristic of a vertebrate in which the notochord (a flexible rod of uniform composition) found in all chordata, ...

and

ribs The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels. The sternum, together known as the thoracic cage, is a semi- ...

, shortened

thorax The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...

, and moderate to severe

scoliosis Scoliosis is a condition in which a person's spine has a sideways curve. The curve is usually "S"- or "C"-shaped over three dimensions. In some, the degree of curve is stable, while in others, it increases over time. Mild scoliosis does not t ...

and

kyphosis Kyphosis is an abnormally excessive convex curvature of the spine as it occurs in the thoracic and sacral regions. Abnormal inward concave ''lordotic'' curving of the cervical and lumbar regions of the spine is called lordosis. It can result fr ...

. Individuals with Jarcho-Levin typically appear to have a short trunk and neck, with arms appearing relatively long in comparison, and a slightly protuberant

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...

. Severely affected individuals may have life-threatening pulmonary complications due to deformities of the thorax. The syndrome was first described by Saul Jarcho and Paul M. Levin at

Johns Hopkins University Johns Hopkins University (Johns Hopkins, Hopkins, or JHU) is a private university, private research university in Baltimore, Maryland. Founded in 1876, Johns Hopkins is the oldest research university in the United States and in the western hem ...

in 1938.

Genetics

Types include:

Diagnosis

Subtypes and characteristics

In 1968, Dr.

David Rimoin David Lawrence Rimoin (November 9, 1936 – May 27, 2012) was a Canadian American geneticist. He was especially noted for his research into the genetics of skeletal dysplasia (dwarfism), inheritable diseases such as Tay–Sachs disease, and dia ...

and colleagues in

Baltimore Baltimore ( , locally: or ) is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland, fourth most populous city in the Mid-Atlantic (United States), Mid-Atlantic, and List of United States cities by popula ...

first distinguished between the two major presentations of Jarcho-Levin. Both conditions were characterized as failures of proper vertebral segmentation. However, the condition within the family described in their article appeared to be inherited in an

autosomal dominant In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...

fashion and had a less severe course than that reported by other investigators. They specified their condition as spondylocostal dysplasia, which has since become known as spondylocostal dysostosis. The subtype of Jarcho-Levin with which they contrasted their reported cases to is now known as spondylothoracic dysplasia.

Spondylothoracic dysplasia

Spondylothoracic dysplasia, or STD, has been repeatedly described as an autosomal recessively inherited condition that results in a characteristic fan-like configuration of the ribs with minimal intrinsic rib anomalies. Infants born with this condition typically died early in life due to recurrent respiratory infections and pneumonia due to their restricted thorax. Recently, a report has documented that actual mortality associated with STD is only about 50%, with many survivors leading healthy, independent lives.

Spondylocostal dysostosis

In contrast to STD, the subtype spondylocostal dysostosis, or SCD features intrinsic rib anomalies, in addition to vertebral anomalies. Intrinsic rib anomalies include defects such as bifurcation, broadening and fusion that are not directly related to the vertebral anomalies (such as in STD, where extensive posterior rib fusion occurs due to segmentation defects and extreme shortening of the thoracic vertebral column). In both subtypes, the pulmonary restriction may result in pulmonary hypertension, and have other potential cardiac implications.

Management

Prognosis

Babies born with Jarcho-Levin may be very healthy and grow up to lead normal lives. However, many individuals with Jarcho-Levin suffer from problems of respiratory insufficiency secondary to volume-restricted thoraces. These individuals will often develop pulmonary complications and die in infancy or early childhood. The disparity in outcomes of those with the syndrome is related to the fact that Jarcho-Levin actually encompasses two or more distinct syndromes, each with its own range of prognoses. The syndromes currently recognized as subtypes of Jarcho-Levin are termed

spondylothoracic dysplasia Spondylocostal dysostosis, also known as Jarcho-Levin syndrome (JLS), is a rare, heritable axial skeleton growth disorder. It is characterized by widespread and sometimes severe malformations of the vertebral column and ribs, shortened thorax, an ...

and

spondylocostal dysostosis Spondylocostal dysostosis, also known as Jarcho-Levin syndrome (JLS), is a rare, heritable axial skeleton growth disorder. It is characterized by widespread and sometimes severe malformations of the vertebral column and ribs, shortened thorax, an ...

. The disease is related to the SRRT gene.

Epidemiology

To date about 20 cases of Spondylocostal dysostosis have been reported in literature.

Terminology

"Type 1" is also known as "Jarcho-Levin syndrome", or "JLS". While clinicians almost unanimously refer to the syndrome as "Jarcho-Levin", reports have variously labelled or referred to the condition as all of the following: Hereditary malformations of the vertebral bodies, hereditary multiple hemivertebrae, syndrome of bizarre vertebral anomalies, spondylocostal dysplasia, spondylothoracic dysplasia, costovertebral anomalies, costovertebral dysplasia, spondylothoracic dysplasia, occipito-facial-cervico-thoracic-abdomino-digital dysplasia (deemed "ridiculously long" and "unwarranted" by OMIM), and spondylocostal dysostosis. A closely related condition termed "Costovertebral segmentation defect with mesomelia and peculiar facies", or Covesdem syndrome, was first described in 1978 in India.

References

External links

{{DEFAULTSORT:Jarcho-Levin Syndrome Genetic disorders by system