Question: What is (are) Schwartz Jampel syndrome type 1 ?
Answer: Schwartz Jampel syndrome type 1 (SJS1) is a genetic disorder that affects bone and muscle development. Signs and symptoms may include muscle weakness and stiffness, abnormal bone development, joint contractures, short stature, small, fixed facial features, and eye abnormalities (some of which may impair vision). SJS1 can be divided into two subtypes differentiated by severity and age of onset. Type 1A, considered classic SJS, is the most commonly recognized type. Individuals with type 1A typically develop more mild symptoms later in childhood, while individuals with type 1B have symptoms that are more severe and are apparent immediately after birth. SJS1 is caused by mutations in the HSPG2 gene which makes a protein called perlecan. SJS1 is thought to be inherited in an autosomal recessive manner; however, some cases reported in the medical literature suggest an autosomal dominant inheritance pattern. Treatment for both type 1A and 1B aims to normalize muscle activity through various methods including massage and stretching, medications such as Botulinum toxin, and surgery. There is a more severe, distinct condition called Stuve-Wiedemann syndrome which is caused by mutations in the LIFR gene. At one time cases of Stuve-Wiedemann syndrome were referred to as Neonatal Schwartz Jampel syndrome type 2. Click on the link above to learn more about this syndrome.
Source: GARD

Question: What causes Schwartz Jampel syndrome type 1 ?
Answer: What causes Schwartz Jampel syndrome type 1? Schwartz Jampel syndrome type 1 (SJS1) is caused by mutations in the HSPG2 gene. The HSPG2 gene codes for the protein perlecan, which is found in muscle and cartilage. Although the role of the perlecan protein is not fully understood, it is thought to play an essential role in many biological activities such as cell signaling and cellular structure. In SJS1, it is suspected that a disturbance in perlecan function leads to a deficiency of acetylcholinesterase, an enzyme involved in breaking down acetylcholine, a neurotransmitter that sends messages between nerves, leading to muscle contraction. If acetylcholine is not broken down, it may lead to an prolonged muscle contraction or stiffening of the muscles (myotonia).
Source: GARD

Question: Is Schwartz Jampel syndrome type 1 inherited ?
Answer: How is Schwartz Jampel syndrome type 1 inherited? The majority of cases of Schwartz Jampel syndrome type 1 (SJS1) are inherited in an autosomal recessive pattern. This means that to have the disorder, a person must have a mutation in both copies of the responsible gene in each cell. Individuals with SJS1 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). Rarely, cases of SJS1 with autosomal dominant inheritance have been reported. This means that having a change (mutation) in only one copy of the responsible gene in each cell is enough to cause features of the condition.
Source: GARD

Question: How to diagnose Schwartz Jampel syndrome type 1 ?
Answer: How is Schwartz Jampel syndrome type 1 diagnosed? The diagnosis of Schwartz Jampel syndrome type 1 (SJS1) is suspected based on clinical findings including characteristic facial features, skeletal features, and muscle stiffness (myotonia). Studies that may be useful in diagnosing SJS1 include: blood tests (which may show elevated serum creatine kinase or adolase); imaging studies; muscle biopsy; and electromyography (EMG)/nerve conduction studies. Genetic testing of the HSPG2 gene may additionally be helpful to confirm the diagnosis.
Source: GARD

Question: What are the treatments for Schwartz Jampel syndrome type 1 ?
Answer: How might Schwartz Jampel syndrome type 1 be treated? Treatment of Schwartz Jampel syndrome type 1 (SJS1) aims to reduce stiffness and cramping of muscles. This might include nonpharmacologic modalities such as massage, warming of muscles, and gradual strengthening exercises. Medications that might be utilized include muscle relaxants and anti seizure medications, particularly Carbamazepine. Botox might additionally be used to relieve eye symptoms such as blepharospasm (involuntary blinking of spasm of eyes). If Botox is not successful in managing eye symptoms, a variety of surgical techniques have been found to be effective. When considering surgery as an option, an important consideration is the risk for malignant hyperthermia, which could lead to adverse outcomes.
Source: GARD