Wolf-Hirschhorn Syndrome

Wolf-Hirschhorn syndrome is a genetic disorder that is caused due to deletion of a part of the chromosome 4. It is characterized by several distinctive symptoms such as a unique and unusual facial appearance, intellectual disability, extreme developmental delays, seizures and several other forms of congenital defects.

Wolf-Hirschhorn syndrome tends to occur in approximately 1 out of 50,000 births. It is however believed that this rate of incidence is somewhat an underestimation as a number of individuals affected by the condition are never diagnosed.

The exact reasons are unknown, but more females are affected by Wolf-Hirschhorn syndrome as compared to males.

Symptoms of Wolf-Hirschhorn syndrome

Some of the signs and symptoms of Wolf-Hirschhorn syndrome are discussed below:

Facial characteristics:

• A majority of the individuals affected by Wolf-Hirschhorn syndrome have unique facial features that include a high temple and a flat, brad nasal bridge. This appearance is often referred to as the ‘Greek warrior helmet’ look.
• The chin is tiny and receding
• The eyes tend to project out and are usually widely spaced.
• The mouth is downward slanting
• The distance between the upper lip and the nose is very short
• The ears are poorly developed with loosely hanging skin and small holes
• The head is smaller is size as compared to the normal standards
• The face may feature asymmetry

Intellectual disabilities:

• Individuals affected by Wolf-Hirschhorn syndrome may experience intellectual deficiencies that may range from mild to severe. As compared to other individuals with various forms of intellectual defects, people with Wolf-Hirschhorn syndrome have stronger social skills, but are generally weaker in language and communication skills.
• A number of affected children are prone to seizures and sits that cannot be resolved with medications. As these children grow up, the seizure episodes fade away.

Developmental delays:

• Individuals affected by Wolf-Hirschhorn syndrome tend to experience delays in development and growth.
• A majority of the affected individuals have a short stature
• The delays in growth and development begin before birth itself and may affect the fetus.
• Infants with Wolf-Hirschhorn syndrome tend to experience feeding problems as well as difficulties in putting on weight. Thus there is failure to flourish
• Sitting, walking, standing and other motor skills are considerably delayed
• The muscles are underdeveloped and the muscle tone is frail

Other defects:

• Individuals affected by Wolf-Hirschhorn syndrome may develop skin irregularities such as dry or spotted skin.
• Dental abnormalities such as cleft palate which involves the presence of an opening in the roof of the mouth; a cleft lip or missing teeth may also be visible
• Skeletal irregularities such as abnormal spine curvature, resulting in conditions like scoliosis, may be also be present in people with Wolf-Hirschhorn syndrome
• Problems of the heart, the eyes, the brain and the genitourinary system may result from the disorder

There is another disorder known as Pitt-Rogers-Danks syndrome, which has symptoms and features similar to those elicited by Wolf-Hirschhorn syndrome. It has now been accepted that both the syndromes are essentially part of a single condition with different signs and symptoms.

Causes of Wolf-Hirschhorn syndrome

Wolf-Hirschhorn syndrome is caused due to an erasure of the genetic material present near the last part of the short arm of chromosome 4.

The size of this erasure differs from one affected individual to another. As per research conducted on Wolf-Hirschhorn syndrome, it is known that larger deletions tend to result in greater number of extreme physical defects and intellectual deficits as compared to smaller deletions

A number of genes such as LETM1, WHSC1 and MSX1get deleted along with other genes due to Wolf-Hirschhorn syndrome. The exact functions of these genes are unknown, but it is understood that they play an important role in early growth and development.

The deletion of WHSC1 gene is thought to be associated with the facial characteristics and developmental delays caused by the disorder. Deletion of the MSX1 gene may cause the dental anomalies, cleft palate, etc., while deletion of LETM1 gene tends to result in abnormal brain electrical activity and seizures.

A majority of the cases of Wolf-Hirschhorn syndrome are not inherited and are caused due to random events during the development of maternal eggs and/or paternal sperm, or during early conception stages, which result in the deletion of genetic material from chromosome 4.

A very small percentage of the cases of Wolf-Hirschhorn syndrome are inherited and is generally passed on from a parent who is a carrier of a copy of chromosome 4 that has a deleted part.

Treatment 

There are no specific methods to treat Wolf-Hirschhorn syndrome. The treatment is focused at correcting and reducing the various symptoms of the disorder. Also, the treatment tends to differ from one affected person to another. A person with Wolf-Hirschhorn syndrome who has cleft lip may opt for surgery to correct, while another patient with cleft lip may not want to have surgery.

Similarly, the various symptoms of Wolf-Hirschhorn syndrome such as eye abnormalities, skeletal defects, hearing loss, feeding difficulties, cardiovascular problems, etc. may be treated as per the individual cases.

Wolf-Hirschhorn Syndrome life expectancy

Statistically speaking, it has been observed that nearly 35 to 38 percent of people who have Wolf-Hirschhorn Syndrome die within two years of birth.  The condition is rare and has been noticed only one in 50,000 people. Mostly people live up to their late 20s and in some cases, up to their forties.

Wolf-Hirschhorn Syndrome Pictures