Werdnig–Hoffman disease

Werdnig–Hoffman disease

Werdnig-Hoffman disease (also known as "Severe infantile spinal muscular atrophy", or "spinal muscular atrophy type I") is an autosomal recessive neuromuscular disease. It is the most severe form of spinal muscular atrophy, which is one of a number of neuromuscular diseases classified as a type of muscular dystrophy.

Werdnig-Hoffman affects the lower motor neurons only.

Causes

It has been linked to an abnormal survival motor neuron (SMN) gene. ub

Eponym

It is named for Johann Hoffmann and Guido Werdnig.

Symptoms

It is evident before birth or within the first few months of life. There may be a reduction in fetal movement in the final months of pregnancy. Affected children never sit or stand unassisted and will require respiratory support to survive beyond the age of 2. Other symptoms include:

• Fasciculations (quivering) of the tongue
• Marked Hypotonia in legs, arms, rib, chest & bulbar muscles (Patient lies in a frog-leg position, i.e. hips abducted & knees flexed)
• Flaccid quadriplegia
• Difficulty breathing
• Poor feeding
• Weak cry
• Areflexive extremities

Diagnosis

• Electromyogram (EMG) will show fibrillation & muscle denervation
• Serum creatine kinase may be normal or increased

Key clinical point is hypotonia associated with absent reflexes in early infancy

Genetics

Werdnig-Hoffman disease has an autosomal recessive pattern of inheritance.

Werdnig-Hoffman disease is inherited in an autosomal recessive pattern, which means the defective gene is located on an autosome, and two copies of the gene - one from each parent - are required to inherit the disorder. The parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but do not have the disorder.

Treatment

Treatment is symptomatic and supportive and includes treating pneumonia, curvature of the spine and respiratory infections, if present. Also, physical therapy, orthotic supports, and rehabilitation are useful. For individuals who survive early childhood, assistive technology can be vital to providing access to work and entertainment. Genetic counseling is imperative.

Tracheostomy is often (but not always) a part of the treatment plan.........

Prognosis

Children with Werdnig-Hoffmann disease / SMA Type 1 face a difficult battle. The patient's condition tends to deteriorate over time, depending on the severity of the symptoms.

The child is constantly at risk of respiratory infection and pneumonia.

Poor chewing and swallowing may lead to malnutrition; supplemental tube feedings may be required through the nose or directly into the stomach.

Recurrent respiratory problems (the primary cause of morbidity in this condition) mean that mechanical support for breathing—usually initially in the form of BiPAP and later often tracheostomy and ventilation—are necessary for the baby to have any chance of long-term survival.

Affected children never sit or stand and usually die before the age of 2 without breathing support.

However, some individuals have survived to become adults.

See also

• Motor neuron disease
• Spinal muscular atrophy

External links

• Fight SMA / Andrew's Buddies
• Families of Spinal Muscular AtrophyFamilies of SMA is a non-profit organization based in Illinois with over 30 chapters throughout the US and international affiliates. Mission: Families of SMA is dedicated to creating a treatment and a cure (for SMA) by 1) Funding and advancing a comprehensive research program; 2) Supporting SMA families through networking, information and services; 3) Improving care for all SMA patients; 4) Educating health professionals and the public about SMA; 5) Enlisting government support for SMA, and 6) Embracing all touched by SMA in a caring community. The FSMA vision is: A world where Spinal Muscular Atrophy is treatable and curable. FSMA is one of the largest funding organizations for SMA research, including funding for basic research, drug research, clinical research, and a large clinical trials network. FSMA sponsors the Annual SMA Family and Professionals Conference every year in June, which is open to any families touched by SMA; and the International SMA Research Meeting, which brings together hundreds of researchers from all over the world. The Families of SMA website: www.curesma.org.
• SMA at NINDS
• SMA Support