About 1p36 deletion syndrome

What is 1p36 deletion syndrome?

1p36 deletion syndrome facts

  • Introduction to the 1p36 deletion syndrome – how individuals get chromosomes with missing DNA
  • 1p36 deletion syndrome stands for the following: 1 is the chromosome number that has deleted DNA, p is the short arm of the chromosome (shortest length of DNA above the centromere) that contains designated area 36 that is missing DNA
  • DNA missing from area 1p36 is responsible for the broad range of symptoms such as changes in facial structures, severe learning disabilities, severe oral communication problems, heart, muscle, breathing, eye and other problems
  • Not all affected individuals develop all problems; the severity is likely related to which areas and how much DNA is missing in 1p36
  • Treatment for 1p36 deletion syndrome is mainly aimed at reducing the severity of symptoms with consultations with experts in the medical, surgical and behavior fields.
  • Each person with 1p36 deletion syndrome is an individual with problems specifically related to their 1p36 DNA loss; with appropriate consultation and effort on both the affected individual and their family or caregiver, a chance to develop rewarding relationships should be available for many people
  • The genetic problem is so new that life expectancy and overall prognosis are not yet well defined; there are reports that some individuals with 1p36 deletion syndrome live to adulthood.

What is 1p36 deletion syndrome?

As humans, we all should share 23 chromosomes from each parent, for a total of 46. But what happens when some of the genetic material (genes made from DNA) in the chromosomes is missing? The outcome depends on the functions that the genetic material control. Unfortunately, in a relatively newly identified problem, 1p36 deletion syndrome, (first deletion noted in 1981 and in 1997, the clinical features first outlined), a small segment of missing DNA results in large problems for individuals missing the DNA and for their families.

The name of the problem is 1p36 deletion syndrome. This numeric name means that it affects chromosome # 1, the largest human chromosome. It precisely affects the area on the #1 chromosome that is on a short arm of the chromosome (p means the short arm above the centromere that joins the two parental copies of chromosome 1, and area 36 is where the missing DNA should be located). In recent years (about 2005-08), recent diagnostic tests known as fluorescent in situ hybridization (FISH) and microarray comparative genomic hybridization (array CGH) have been developed to definitively diagnose the 1p36 deletion syndrome. CGH may determine about how much DNA is missing.



What are the symptoms for 1p36 deletion syndrome?

Unfortunately, for the affected individuals and family, missing DNA in this section is very influential on a person's overall development and is often unnoticed until the newborn or infant is noted to miss physical or developmental landmarks. These landmarks that are missed or severely delayed comprise the symptoms and signs of 1p36 deletion syndrome. Not all symptoms will be present in each individual because there is variation from person to person and, in general, most researchers think that the more DNA missing from 1p36, the more intense or apparent these symptoms will appear.

Many individuals will have a small head size that is short and wide; many have noticeable facial features of deep-set eyes with straight-appearing eyebrows, a sunken–appearing face with a broad flat nose and an elongated area from nose to mouth, a pointed chin, and low-set ears that are rotated backwards and are abnormally shaped. Some individuals are preliminarily diagnosed from their appearance described above. Others may have less noticeable physical symptoms and require FISH or CGH tests for diagnosis.

To confirm or establish the diagnosis it is appropriate to test any individual suspected of having 1p36 deletion syndrome as follows:

  • Conventional cytogenetic studies to detect large deletions (i.e., > 5 Mb) and more complex cytogenetic rearrangements (unbalanced chromosome translocations)
  • FISH with at least two subtelomeric region-specific probes (Vysis 1p subtel probe, Vysis p58 probe; D1Z2 Oncor probe or CEB108/T7) to detect unbalanced translocations and to identify parental chromosome rearrangements
  • Deletion/duplication analysis by CMA to detect smaller deletions (i.e., > 5 Mb) or interstitial deletions or complex rearrangements

There are other problems (symptoms) that many individuals with 1p36 deletion syndrome develop:

  • About 90% have severe learning disabilities
  • About 75% will have no ability to form words, the other approximate 25% will only develop a few words or phrases
  • About 70% develop types of heart problems
  • About 50% will develop seizures, behavior problems, and hearing problems
  • Other problems such as weak muscle tone, breathing problems, eye problems, swallowing problems, genital malformations (usually minor in males), and metabolic problems have been reported.



What are the causes for 1p36 deletion syndrome?

As humans, we all should share 23 chromosomes from each parent, for a total of 46. But what happens when some of the genetic material (genes made from DNA) in the chromosomes is missing? The outcome depends on the functions that the genetic material controls. Unfortunately, in a relatively newly identified problem, 1p36 deletion syndrome, (first deletion noted in 1981 and in 1997, the clinical features first outlined), a small segment of missing DNA results in large problems for individuals missing the DNA and for their families.

The name of the problem is 1p36 deletion syndrome. This numeric name means that it affects chromosome # 1, the largest human chromosome. It precisely affects the area on the #1 chromosome that is on a short arm of the chromosome (p means the short arm above the centromere that joins the two parental copies of chromosome 1, and area 36 is where the missing DNA should be located). In recent years (about 2005-08), recent diagnostic tests known as fluorescent in situ hybridization (FISH) and microarray comparative genomic hybridization (array CGH) have been developed to definitively diagnose the 1p36 deletion syndrome. CGH may determine about how much DNA is missing.



What are the treatments for 1p36 deletion syndrome?

Treatment is limited; symptomatic treatment is the usual treatment available. The heart, eye, muscle tone, and swallowing problems may be reduced by specialists in those fields; the earlier the diagnosis and treatment, the more likely these problems will become manageable or minimized. Some clinicians report good results with behavior modification training. Some affected individuals do well and can participate in many social events, but not all individuals are successful.

Compassion, patience and understanding of the extent of an individual's capabilities can allow an individual to have a loving and rewarding relationship with family and friends. Some affected individuals may be able to learn to communicate with body and sign language; this ability may take considerable effort and training on both the affected person and caregiver's part to develop.

 



What are the risk factors for 1p36 deletion syndrome?

Genetic material from a particular area on the short (p) arm of chromosome 1 is deleted, leading to the condition known as 1p36 deletion syndrome. The loss of numerous genes in this region is likely related to the 1p36 deletion syndrome's signs and symptoms. Each person with the deletion has a different size.

1. The majority of 1p36 deletion syndrome instances are not hereditary. They are the outcome of a chromosomal deletion that happens by chance either during the creation of sperm or egg cells or during the early stages of fetal development. Most affected individuals have no family history of the illness.
2. A portion of the chromosome with deletion is inherited from an unaffected parent in about 20% of patients with 1p36 deletion syndrome. In these situations, the parent has a balanced translocation, a chromosomal rearrangement in which neither genetic material is gained nor lost.
3. Healthy translocations that are balanced can occasionally become unbalanced as they are handed down to the following generation.
4. Unbalanced translocations can be inherited, and children that inherit them may experience chromosomal rearrangements with additional or missing genetic material.
5. The short arm of chromosome 1 is missing genetic material in people with 1p36 deletion syndrome who inherit an imbalanced translocation, which causes birth abnormalities and other health issues typical of this illness.

Symptoms
Deep-set eyes,Pointed chin
Conditions
Midface hypoplasia,Long area between nose and mouth
Drugs
Anti-seizure medications



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