What is 1p36 Deletion Syndrome

1p36 Deletion Syndrome is a rare genetic condition caused by the loss of a specific segment of genetic material from the short arm (p) of chromosome 1. It is characterized by intellectual disability, delayed development, distinct facial features, and a range of potential physical health challenges that vary significantly between individuals.

What causes 1p36 Deletion Syndrome?

1p36 Deletion Syndrome occurs due to a chromosomal microdeletion, meaning a small piece of DNA is missing from the end of the first chromosome. In most cases, this deletion happens spontaneously (de novo) during the formation of reproductive cells or early embryonic development. While it is rarely inherited from a parent, a clinical geneticist can perform parental testing to determine if a balanced translocation is present, which would carry a higher risk of recurrence.

How does 1p36 Deletion Syndrome affect the body?

The clinical presentation of 1p36 Deletion Syndrome is broad, reflecting the many genes located in the deleted region. Common manifestations include:

• Developmental delays: Significant speech and motor skill delays, with many individuals remaining non-verbal.


• Physical features: Distinctive traits such as deep-set eyes, a straight eyebrow line, a pointed chin, and midface hypoplasia.


• Neurological symptoms: Epilepsy occurs in approximately 50-75% of individuals diagnosed with 1p36 Deletion Syndrome.


• Structural differences: Potential heart defects (such as cardiomyopathy), skeletal abnormalities, and vision or hearing impairments.

How common is 1p36 Deletion Syndrome?

Estimates suggest that 1p36 Deletion Syndrome occurs in approximately 1 in 5,000 to 10,000 live births. It is considered one of the most common terminal deletion syndromes. The condition affects males and females equally, and it is found in all ethnic and geographic populations worldwide. Within the DiseaseMaps.org community, 22 individuals have connected to share their experiences and support one another through the challenges of living with this diagnosis.

How is 1p36 Deletion Syndrome different from other conditions?

Unlike some syndromes defined by a single gene mutation, 1p36 Deletion Syndrome is a "contiguous gene syndrome." Because the size and location of the deletion can vary, the severity and specific combination of symptoms are unique to each person. This variability is what distinguishes it from more uniform genetic conditions.

Next steps

• Consult a clinical geneticist to confirm the diagnosis via chromosomal microarray analysis.


• Schedule multidisciplinary evaluations with a pediatric cardiologist, neurologist, and developmental pediatrician.


• Join the DiseaseMaps.org community to connect with other families navigating 1p36 Deletion Syndrome.


• Explore early intervention services, including speech, physical, and occupational therapy.

Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): 1p36 deletion syndrome overview.


• Orphanet: Rare disease database entry for 1p36 deletion syndrome.


• OMIM (Online Mendelian Inheritance in Man): Entry #607872.


• 1p36 Deletion Support & Awareness (1p36DSA) Foundation.