1p36 deletion syndrome | What we need to know

1p36 deletion syndrome is a chromosomal disorder that usually causes severe mental retardation. People with the syndrome have difficulty speaking and speaking. They may have tantrums (outbursts of emotion, mostly caused by anger or frustration) or other behavioral problems. Most have structural brain abnormalities and seizures. Patients usually have congenitally weak muscle tone (hypotension) and difficulty swallowing (dysphagia).

1p36 deletion syndrome is caused by the deletion of genetic material from a specific region on the short (p) side of the first chromosome. The signs and symptoms of 1p36 deletion syndrome are likely caused by the loss of several genes in this region.

Synonyms of disease

• chromosomal 1p36 deletion syndrome;
• Distal monosomy 1p36;
• Monosomy 1p36 syndrome.

Etiology

In most cases, 1p36 deletion syndrome is not inherited. It results from a chromosomal deletion that occurs as a random event during the formation of germ cells (egg or sperm) or during the early stages of fetal development.

About 1 percent of people with 36p20 deletion syndrome inherit the mutated chromosome from a healthy parent. In these cases, the parent undergoes a chromosomal rearrangement called a balanced translocation, in which the genetic material is not completely gained or lost. A balanced translocation usually does not cause health problems; However, it can cause various syndromes when passed from parent to offspring.

Symptoms

People with 1p36 deletion syndrome have:

• retardation of growth and development; (85%)
• intellectual impairment;
• convulsions; (72%)
• unbalanced behavior; (56%)
• vision problems; (75%)
• hearing loss; (56%)
• congenital heart defects;
• Cardiomyopathy and kidney abnormalities;
• small head (microbrachycephaly);
• distinctive features, including deep-set eyes; (50%)
• hypoplasia of the middle face;
• clinodactyly and/or short fifth finger; (64%)
• wide flat nose; (65%)
• pointed chin; (80%)
• ears turned back and irregularly shaped; (59%)
• Cardiovascular malformations and cardiomyopathy are among the most common phenotypes caused by chromosome 1p36 deletion, affecting approximately 5000 in every 1 newborns.

Diagnosis

Nowadays, diagnostics of 1p36 deletion syndrome is not difficult. It is mainly based on laboratory data. A chromosomal defect is detected by a genetic test, and this test is performed based on clinical signs.

There are two main types of tests available to prevent fetal syndromes during pregnancy (prenatal period): screening tests and diagnostic tests. Screening and diagnostic tests determine whether a fetus has a low or high chance of developing various syndromes. If screening tests show that you have a high risk of having a baby with 1p36 deletion syndrome, it is recommended that you also have a diagnostic test to determine whether the fetus has the genetic disorder.

1. Screening Tests – A prenatal screening test can determine if your baby is more or less likely to have birth defects, many of which are genetic disorders. These tests include blood tests, specific ultrasounds, and prenatal cell-free DNA screening.

2. Diagnostic tests – after the screening test, the final answer is given by the diagnostic test, which checks the genetic material of the fetus and therefore can also find out whether the fetus has a genetic disorder. Invasive and non-invasive prenatal diagnostic tests ((NIPT) Verasity, Veragen) are the only, safe and effective way to confirm the diagnostics.

Be aware that some diagnostic tests, such as chorionic villus sampling and amniocentesis, carry a small risk of miscarriage.

Learn more about prenatal diagnostics → (https://synevo.ge/prenatal-screening/)

Treatment

There is no cure for 1p36 deletion syndrome. Treatment is focused on alleviating the symptoms of the disease and early detection through laboratory tests. It is especially important to take appropriate medications for endocrine and neurological manifestations, such as anticonvulsant medications, after a doctor's visit.

source

• 1. https://medlineplus.gov/genetics/condition/1p36-deletion-syndrome/#causes
• 2. https://pubmed.ncbi.nlm.nih.gov/24454898/ Shaffer LG, Lupski JR. Molecular mechanisms for constitutional chromosomal rearrangements in humans. Annu Rev Genet. 2000;34:297–329. – PubMed
• 3. Shapira SK, McCaskill C, Northrup H, et al. Chromosome 1p36 deletions: the clinical phenotype and molecular characterization of a common newly delineated syndrome. Am J Hum Genet. 1997;61(3):642–650. - PMC - PubMed

Alexander Tsintsabadze