Schwartz-Jampel Syndrome: A Rare, Inherited Genetic Disorder

Symptoms, Causes and Treatment Options for Schwartz-Jampel Syndrome

prenatal ultrasound
Andersen Ross/DigitalVision/Getty Images

Schwartz-Jampel syndrome (SJS) is a rare, inherited disorder which causes abnormalities of the skeletal muscles.

Some of the abnormalities caused by the disorder may include some or all of the following:

  • Myotonic myopathy (muscle weakness and stiffness) 
  • Bone dysplasia (abnormal bone development)
  • Joint contractures (permanent bending or extension of certain joints in a fixed position)
  • Dwarfism (growth delays resulting in abnormally short stature)

    SJS is an autosomal recessive condition, meaning that an individual needs to inherit two defective genes, one from each parent, in order to develop the syndrome.

    Types of Schwartz-Jampel Syndrome

    There are several subtypes of Schwartz-Jampel syndrome. Type I, considered the classic type, has two subtypes that have been traced to a defective gene on chromosome 1:

    • Type IA becomes apparent later in childhood and is less severe.
    • Type IB is apparent immediately at birth and has more severe symptoms. 

    Schwartz-Jampel syndrome Type II is apparent immediately at birth (a congenital defect). It has somewhat different symptoms than either IA or IB and is not associated with any gene defect on chromosome 1. Therefore, researchers believe Type II is the same disease as Stuve-Wiedermann syndrome. Thus, Type I will be the focus of this article.

    Symptoms of SJS

    The main symptom of Schwartz-Jampel syndrome is muscle stiffness.

    This stiffness is similar to that of Stiff-person syndrome or Isaacs syndrome, but the stiffness of Schwartz-Jampel syndrome is not relieved by medication or sleep. Additional symptoms may include:

    • A short stature
    • Flattened facial features, narrow corners of the eyes, and a small lower jaw
    • Joint deformities such as short neck, outward curving of the spine (kyphosis), or protruding chest (pectus carinatum, also called "pigeon chest")
    • Abnormalities of bone and cartilage growth (chondrodystrophy)
    • Many individuals also have several eye (ocular) abnormalities, resulting in varying degrees of visual impairment

    Every SJS case is unique and varies in the range and severity of the associated symptoms, depending on the type of the disorder.

    How the Condition Is Diagnosed

    SJS is usually detected during the first few years of life, most often at birth. Parents may notice an infant's stiff muscles during diaper changes, for example. This stiffness plus the facial features common to the syndrome are usually sufficient for diagnosis. Further studies of muscle and nerve conduction in the child will be conducted to confirm abnormalities consistent with SJS. Skeletal abnormalities associated with SJS may be confirmed by imaging studies or other types of testing.

    In some rare cases, prenatal (before birth) diagnosis of SJS may be possible through the use of an ultrasound to see if the fetus has characteristics that point to SJS or other developmental abnormalities.

    Causes of Schwartz-Jampel Syndrome

    Since SJS is inherited in an autosomal recessive manner, if an individual is born with the syndrome both of his parents are carriers of the defective gene. Each future child that these parents have will have a 1 in 4 chance of being born with the syndrome.

    SJS is a rare disorder that does not shorten the lifespan. Both males and females are affected equally by the disease and SJS type II appears to be most common in individuals of United Arab Emirates descent. More than 85 cases have been recorded of both the classical (type I) and the more severe neonatal form (type II) of the disorder. 

    Treatment for Symptoms

    There is no cure for Schwartz-Jampel syndrome, so treatment focuses on reducing symptoms of the disorder. Medications that are useful in other muscle disorders, such as anticonvulsants and anti-arrhythemics may be helpful. However, the muscle stiffness in Schwartz-Jampel syndrome may worsen slowly over time, so using means other than medication may be preferable. These include muscle massage, warming, stretching, and warming up before exercise.

    Surgery to help treat or correct musculoskeletal abnormalities, such as joint contractures, kyphoscoliosis, and hip dysplasia may be an option for some SJS patients. For some, surgery combined with physical therapy may help improve the ability to walk and perform other movements independently. For visual abnormalities, surgery, corrective glasses, contact lenses or other supportive methods may help improve vision.

    Source:

    Berman, S. (2014). Schwartz-Jampel syndrome. eMedicine. Accessed 02/14/2016 

    National Organization for Rare Disorders.Schwartz-Jampel Syndrome.Accessed 02/14/2016

    Continue Reading