Is Potocki-Lupski syndrome hereditary?

Potocki-Lupski syndrome is a genetic condition caused by a duplication of a specific segment of chromosome 17, but it is rarely inherited from a parent. In the vast majority of cases, Potocki-Lupski syndrome occurs as a de novo (spontaneous) event in the individual, meaning it is not passed down through families.

Is Potocki-Lupski syndrome hereditary?

While Potocki-Lupski syndrome is a genetic condition—meaning it is caused by a change in the individual's DNA—it is typically not "hereditary" in the traditional sense of being passed from parent to child. The condition is caused by a microduplication of the 17p11.2 region of chromosome 17. Because most cases arise as a de novo mutation during the formation of reproductive cells (sperm or egg) or in early embryonic development, the parents of an affected child usually have normal chromosomes and a very low risk of having another child with the syndrome.

What is the inheritance pattern of Potocki-Lupski syndrome?

Potocki-Lupski syndrome follows an autosomal dominant pattern of inheritance, meaning only one copy of the duplicated chromosome is required to cause the condition. However, because the duplication almost always occurs spontaneously, it is not considered an inherited trait in most diagnosed families. In extremely rare instances where a parent does carry the duplication, there is a 50% chance of passing it to each offspring. Genetic counselors emphasize that for most families, the recurrence risk for future pregnancies is less than 1%, which is only slightly higher than that of the general population due to the rare possibility of germline mosaicism.

How is Potocki-Lupski syndrome diagnosed and tested?

Diagnosis of Potocki-Lupski syndrome is confirmed through specialized genetic testing, typically a chromosomal microarray (CMA) or fluorescent in situ hybridization (FISH) analysis. These tests are designed to detect the specific 17p11.2 duplication. Testing is generally recommended for children presenting with characteristic features, such as developmental delays, failure to thrive in infancy, sleep apnea, or autistic features. For families where a child has been diagnosed, the following steps are standard clinical practice:

• Parental Karyotype or Microarray: To determine if either parent carries the duplication, which helps clarify recurrence risks.


• Genetic Counseling: A session with a certified genetic counselor to discuss the test results, the nature of the duplication, and family planning options.


• Prenatal Diagnosis: For families who have a known balanced translocation or parent with the duplication, options such as chorionic villus sampling (CVS) or amniocentesis can be discussed during future pregnancies.

What is the role of genetic counseling for affected families?

Genetic counseling is a vital resource for families navigating a Potocki-Lupski syndrome diagnosis. A counselor provides essential support by explaining the complex mechanisms of chromosomal duplications and helping parents understand that they did not "cause" the condition through their actions or lifestyle. For those planning future pregnancies, genetic counseling provides a space to discuss testing options, including preimplantation genetic testing (PGT) if a parent is a known carrier. At DiseaseMaps.org, we have seen 14 community members share their personal experiences, which can be an invaluable source of emotional support and peer guidance for newly diagnosed families.

Next steps

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


• Schedule an appointment with a genetic counselor to discuss recurrence risks and family testing.


• Connect with the DiseaseMaps.org community to share experiences with other families affected by Potocki-Lupski syndrome.


• Maintain regular follow-ups with a multidisciplinary team, including developmental pediatricians and cardiologists.

Medical disclaimer: This information is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment from a qualified healthcare provider.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Potocki-Lupski syndrome.


• Orphanet: 17p11.2 microduplication syndrome.


• OMIM (Online Mendelian Inheritance in Man): Potocki-Lupski Syndrome; PTLS.


• Potocki-Lupski Syndrome Foundation: Patient and family support resources.