Wolf-Hirschhorn Syndrome

Wolf-Hirschhorn syndrome is a genetic condition that is present from birth. It is caused due to deletion of a section of chromosome 4. The disorder is characterized by a variety of unique symptoms and defects such as intellectual deficits, unusual facial features, seizures, severe developmental delays, and other kinds of congenital abnormalities.

Wolf-Hirschhorn syndrome has been found to affect about 1 in every 50,000 live births. Researchers however think that this occurrence rate is slightly underestimated as many people who have Wolf-Hirschhorn syndrome are never diagnosed with the condition.

Doctors are not aware about the precise cause of the genetic defect related to Wolf-Hirschhorn syndrome. However, more females have been diagnosed with the disorder as opposed to males.

Wolf-Hirschhorn syndrome Symptoms

Some of the signs and symptoms of Wolf-Hirschhorn syndrome as per the varied categories of abnormalities are listed below:

• Facial features: Most people affected by Wolf-Hirschhorn syndrome elicit distinctive facial characteristics such as a broad and flat nasal bridge and a somewhat high temple. This look of the face is often known as the ‘Greek warrior helmet’ appearance.
  • There may be asymmetrical development of the facial features
  • The eyes are generally wide-set or widely spaced, or crossed. They may project out or bulge.
  • The eyelids are droopy
  • The corner of the eyes may have skin folds
  • The chin is quite small and tapering
  • The mouth may slant downwards
  • The ears tend to be poorly formed and consist of a preauricular tag or pit
  • The space between the nose and the upper lip is lesser than normal
  • As compared to a normal head size, people with Wolf-Hirschhorn syndrome have a smaller head.
  • Delays in development and growth: Delayed development is one of the most common symptoms of Wolf-Hirschhorn syndrome.
    • Growth and developmental delays commence even before birth and can affect the fetus
    • Affected infants may have feeding difficulties. This can cause problems in gaining weight, eventually preventing the child from flourishing and thriving to its full capacity.
    • Underdevelopment of the muscles and poor muscle tone is evident.
    • Different developmental milestones such as crawling, sitting up, walking, etc. may be delayed.
    • Most people affected by Wolf-Hirschhorn syndrome have a short stature.
    • Intellectual deficits: People with Wolf-Hirschhorn syndrome may suffer from intellectual deficits that can vary from minor to severe retardation. As opposed to other persons affected by different kinds of intellectual disabilities, individuals with Wolf-Hirschhorn syndrome tend to be better at social skills. They are however typically weaker in communication and language skills.
      • A lot of children affected by Wolf-Hirschhorn syndrome suffer from fits, convulsions, and seizures that cannot be corrected with medicines. Fortunately, the bouts of seizures resolve on their own as the children grow older.
      • Other abnormal symptoms:There are many other defects that affect Wolf-Hirschhorn syndrome patients including:
        • Affected people may experience varied skin anomalies such as spotted or dry skin.
        • Abnormalities of the eyes, the heart, the genitourinary system, and the brain may also be present.
        • The palm of the hands may have a single crease. The fingerprints may be underdeveloped
        • Abnormal curvature of the spine and other skeletal abnormalities may be present. Hence, Wolf-Hirschhorn syndrome affected individuals are at increased risk to development of scoliosis.
        • Patients may also suffer from different kinds of dental irregularities such as missing or absent teeth, a cleft lip, and/or a cleft palate i.e. an opening in the roof of the mouth.

It may be noted that there is another condition called Pitt-Rogers-Danks syndrome which has characteristics and symptoms that are similar to those of Wolf-Hirschhorn syndrome. It is currently accepted that both these abnormal disorders are basically part of one single disorder with varying signs and symptoms.

Causes  

Wolf-Hirschhorn syndrome is a congenital disorder caused due to deletion of genetic matter occurring in the short arm of chromosome 4.

Wolf-Hirschhorn syndrome is a contiguous gene syndrome which occurs when a chromosome experiences extra or missing material of many genes in the same area of a chromosome.Every time a genetic duplication or deletion occurs, it causes peculiar features that come to be referred to as a specific syndrome. It is not the same as only one specific gene defect causing a syndrome.

Some people with Wolf-Hirschhorn syndrome may show tiny deletion of the short arm of chromosome 4, while other patients may not have up to half of it. It is one of the reasons why some individuals suffer from minor instances of Wolf-Hirschhorn syndrome, while others suffer from more severe cases. It is also known that greater the deletion, the more severe is the syndrome. It may also be noted that the band 4p16.3 has to be missing for a person to suffer from a full expression of Wolf-Hirschhorn syndrome.

People with Wolf-Hirschhorn syndrome have many genes that get deleted, including WHSC1,LETM1, and MSX1 genes. Doctors are not aware about the precise functions of these genes. It is however known that they are crucial to growth and development. A missing WHSC1 gene can result in abnormal facial features and developmental delays. Deletion of MSX1 gene can cause a cleft palate and other dental problems, while LETM1 gene deletion can result in seizures and anomalous electrical activity in the brain.

Most cases of Wolf-Hirschhorn syndromeare caused due to random events during paternal sperm/maternal egg development, or during conception, which cause the deletion of a section of the short arm of chromosome 4. In rare cases, the genetic defect may be passed on by any one of the carrier parents.

Treatment of Wolf-Hirschhorn syndrome

• There is no standard procedure to treat Wolf-Hirschhorn syndrome. As genetic defects cannot be corrected, treatment is aimed at correcting and alleviating the abnormal symptoms.Also, as the severity of symptoms differs from one patient to another, the treatment also varies.
• A cleft palate can cause many problems. Hence, it needs to be corrected via surgery. However, Wolf-Hirschhorn syndrome patients may not necessarily need to surgically correct a cleft lip.
• Similarly, other defects associated with Wolf-Hirschhorn syndrome such as skeletal anomalies, ocular defects, feeding problems, loss of hearing, cardiovascular abnormalities, etc., will be treated according to individual cases. 

Wolf-Hirschhorn Syndrome Life Expectancy

About 35 percent of people who have this syndrome die within two years of birth. There is no concrete information on live expectancy, but it has been seen that while some live to their 20s, others even pass 40 years of age.

Wolf-Hirschhorn Syndrome pictures