1p36 deletion syndrome: Year of the Zebra

1p36 deletion syndrome is a rare genetic disorder where a small portion of the short arm of chromosome 1 is deleted. Now, our DNA is packaged into 23 pairs of chromosomes, one from each parent, for a total of 46 chromosomes.

Each chromosome contains thousands of genes which are essentially the recipes for making every protein found in the body.

Chromosomes are divided into two sections, or arms, hooked together in the middle by a centromere. The shorter arm is called “p”, from the French “petit” that means small; and the long arm is called “q”.

In 1p36 deletion syndrome, the final portion of the short, or “p,” arm of chromosome 1 is deleted, resulting in a loss of genetic material that is essential for development.

In most cases, 1p36 deletions are a result of a de novo mutation, which means they occur on their own without being inherited.

However, in a small number of cases, the deletion can be inherited from one of the parents. Alright, now signs and symptoms of 1p36 deletion syndrome vary depending on the amount of missing genetic material.

Typically, individuals with 1p36 deletion syndrome will have a short stature and unique facial features like a small head with a large, rounded forehead and small, pointed chin; deeply set eyes; straight eyebrows; and epicanthal folds, which are skin folds of the upper eyelids that cover the inner eye.

The nose is usually flat with a wide nasal bridge, and there can be orofacial defects like cleft palate, which is an opening in the roof of the mouth.

Common symptoms include moderate to severe intellectual disability; slower motor development; dysphagia, or difficulty swallowing; and hypotonia, or weak muscle tone, which usually improves with age.

Individuals may also exhibit seizures; vision and hearing problems; dysarthria, or difficulty speaking; and self-harm or other behavioral problems; as well as delayed closure of the fontanelles, or soft spots in the skull.

A special form of cardiomyopathy that affects the formation of the walls of the heart, giving them a “spongy” appearance, may also be present.

This can be associated with other congenital heart defects such as ventricular septal defects. Occasionally individuals may have other gastrointestinal, kidney, or skeletal abnormalities.

Finally, individuals with 1p36 syndrome tend to have chronic medical problems, including feeding difficulties, failure to thrive, and recurrent infections.Diagnosis of 1p36 deletion syndrome can be suspected based on the characteristic facial features and accompanying symptoms.

Confirmation of the diagnosis can be done with karyotyping, a laboratory test that examines each chromosome to detect any missing pieces.

If there is high clinical suspicion but the karyotype is negative, fluorescence in situ hybridization, or FISH, can be used to detect missing pieces of chromosomes that are too small to be seen during karyotyping.

Since 1p36 deletion syndrome is caused by a genetic deletion, there is no known cure. Generally, management focuses on treating congenital heart defects through surgical repair and using medications to improve heart function and manage seizures, if necessary.

Additional interventions may include physical, speech, and occupational therapy in order to maximize the individual’s development and independence.Alright, as a quick recap… 1p36 deletion syndrome is a rare genetic disorder characterized by unique facial characteristics, intellectual disability, seizures, vision and hearing problems, and cardiac abnormalities.

It is caused by a chromosomal deletion affecting the short arm of chromosome 1. Diagnosis is based on karyotype analysis and fluorescence in situ hybridization to find chromosomal abnormalities; and treatment is based on treating life-threatening complications and providing early interventions to support quality