Wolf-Hirschhorn syndrome

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Definition

What is Wolf-Hirschhorn syndrome?

Wolf-Hirschhorn syndrome (WHS) is a genetic disorder that affects many parts of the body. The major features include a characteristic facial appearance, delayed growth and development, intellectual disability, low muscle tone (hypotonia), and seizures. Other features may include skeletal abnormalities, congenital heart defects, hearing loss, urinary tract malformations, and/or structural brain abnormalities.

How common is Wolf-Hirschhorn syndrome?

WHS is an extremely rare disorder. Studies undertaken about 25 years ago suggested that the disorder occurred in approximately 1 in about 50,000 live births with a female to male ratio of 2:1. More recent studies suggest that the frequency of the disorder is underestimated because of misdiagnosis. Please discuss with your doctor for further information.

Symptoms

What are the symptoms of Wolf-Hirschhorn syndrome?

Babies born with Wolf-Hirschhorn syndrome have distinct facial features with wide set eyes, extremely small head, and a beaked nose.

There are significant development delays and the child finds it very difficult to reach his or her developmental milestones on time. There may also be significant growth retardation. Failure to thrive is another classic symptom of Wolf-Hirschhorn syndrome along with hypotonicity, psychomotor retardation, and seizures.

Affected babies also tend to have cleft lip, cleft palate, a short upper lip, and fishmouth appearance.

Children with Wolf-Hirschhorn syndrome may also have such flexed soles that they walk on their toes. Along with this, there may be certain cardiac and renal defects associated with Wolf-Hirschhorn syndrome.

There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.

When should I see my doctor?

If you or your loved one has any signs or symptoms listed above or you have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.

Causes

What causes Wolf-Hirschhorn syndrome?

WHS is caused by a missing piece (deletion) of genetic material near the end of the short (p) arm of chromosome 4 (written as 4p-). The size of the deletion varies among people with WHS, and studies suggest larger deletions tend to result in more severe features.

There is no definite cause found for the deletion. In majority of the cases of Wolf-Hirschhorn syndrome, this deletion occurs spontaneously during embryonic development meaning that the child gets affected by Wolf-Hirschhorn syndrome before he or she is born. In some cases, Wolf-Hirschhorn syndrome occurs due to balanced translocation in one of the parents.

A balanced translocation occurs when two or more chromosome break away from their parent positions and exchange places with the other breakaway group which results in an altered but balanced set of chromosomes. This alteration of the chromosomes does not affect the carrier but definitely affects the carrier’s offspring who has a high risk of developing something like Wolf-Hirschhorn syndrome.

Risk factors

What increases my risk for Wolf-Hirschhorn syndrome?

Many cases of Wolf-Hirschhorn syndrome (WHS) (about 50-60%) are not inherited from a parent and are caused by a new (de novo) deletion of a region of chromosome 4 (called 4p16) that occurs for the first time in the person with WHS. In about 40-45% of cases, the person with WHS has an unbalanced translocation with both a deletion on chromosome 4 and an extra piece (trisomy) of part of another chromosome. In these cases, the unbalanced translocation may be de novo, or inherited from a parent who carries a balanced rearrangement (when parts of chromosomes are rearranged but there is no extra or missing genetic material).

Risks to family members and their children depend on whether the person with WHS has the syndrome due to a de novo deletion or an unbalanced translocation.

Please consult with your doctor for further information.

Diagnosis & treatment

The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.

How is Wolf-Hirschhorn syndrome diagnosed?

A diagnosis of WHS may be suggested by the characteristic facial appearance, growth failure, developmental delays, and seizures. The diagnosis is confirmed by detection of a deletion of the Wolf-Hirschhorn syndrome critical region (WHSCR) by cytogenetic (chromosome) analysis. Conventional cytogenetic analysis detects less than half of the deletions that cause WHS. Fluorescence in situ hybridization (FISH) using a WHSCR probe has much better detection rate than standard karyotype and will detect most patients. However, the diagnostic test of choice is chromosomal microarray, which detects essentially all deletions of the WHSCR and defines the size of the deletion. Chromosomal microarray can also find other chromosome rearrangements, such as extra pieces of other chromosomes that are seen in many patients with WHS.

How is Wolf-Hirschhorn syndrome treated?

Because WHS is so variable, treatment and intervention must be tailored to the affected individual’s needs.

Patients with a known or suspected diagnosis of WHS should have a comprehensive evaluation by an experienced genetics professional. Most patients will need to be followed by multiple subspecialists.

Patients should have a neurology evaluation with evaluation for seizures, detailed cardiology (heart) evaluation, eye exam, hearing exam, kidney evaluation, feeding evaluation, and developmental evaluation as soon as possible after diagnosis.

Kidney function must be monitored on an ongoing basis.

All patients benefit from comprehensive developmental and rehabilitation support including: feeding therapy, assistive communication, speech, physical therapy, occupational therapy, and school support.

Genetic counseling is recommended for families of children with Wolf-Hirschhorn syndrome.

Lifestyle changes & home remedies

What are some lifestyle changes or home remedies that can help me manage Wolf-Hirschhorn syndrome?

If you have any questions, please consult with your doctor to better understand the best solution for you.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Sources

Review Date: February 28, 2018 | Last Modified: February 8, 2018

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