22q13 deletion / Phelan-McDermid Syndrome synonyms

Phelan-McDermid syndrome, also known as 22q13 deletion syndrome, is a rare genetic condition caused by the loss of the distal end of chromosome 22 or a mutation in the SHANK3 gene. The condition is primarily referred to as Phelan-McDermid syndrome in modern clinical literature, though you may encounter it in older records or international databases under various descriptive titles related to its chromosomal origin.

What are the official names and common synonyms for Phelan-McDermid syndrome?

In medical literature, Phelan-McDermid syndrome is the preferred clinical designation. However, because the condition was historically identified by its cytogenetic location, you will frequently see it referred to as 22q13 deletion syndrome or 22q13.3 deletion syndrome. These names describe the specific location on the chromosome where the genetic material is missing. Researchers and clinicians use these terms interchangeably, though "Phelan-McDermid syndrome" is now the standard naming convention to honor the researchers who first characterized the clinical features of the condition.

Why does this condition have multiple names?

The evolution of terminology for 22q13 deletion syndrome reflects the history of genetic discovery. Before the role of the SHANK3 gene was fully understood, the condition was defined strictly by the physical deletion observed on chromosome 22. As diagnostic technology improved—moving from basic karyotyping to high-resolution chromosomal microarray analysis—scientists realized that mutations strictly within the SHANK3 gene could cause the same clinical presentation even without a visible deletion. Consequently, the term Phelan-McDermid syndrome was adopted as an umbrella term to cover both chromosomal deletions and isolated gene mutations, ensuring that patients receive a consistent diagnosis regardless of the specific underlying genetic mechanism.

How is the condition classified in global medical databases?

Understanding how Phelan-McDermid syndrome is indexed can assist in navigating medical records and insurance documentation. Below are the primary identifiers used in major medical classification systems:

• Orphanet: Listed as ORPHA:635, under the name Phelan-McDermid syndrome.


• OMIM (Online Mendelian Inheritance in Man): Cataloged as #606232, titled "Phelan-McDermid Syndrome."


• ICD-10/11: While there is no single specific code for every rare disease, it is often coded under broader categories for chromosomal abnormalities, such as Q93.5 (other deletions of part of a chromosome).


• NIH GARD: Recognizes the condition primarily as Phelan-McDermid syndrome, with 22q13 deletion syndrome as the primary synonym.

Which name should families and patients use?

While 22q13 deletion syndrome is still widely understood by geneticists, Phelan-McDermid syndrome is the preferred term used by patient advocacy groups and modern clinical practices. Our community at DiseaseMaps.org, which includes 35 individuals living with this diagnosis, utilizes the name Phelan-McDermid syndrome to foster a unified identity and to connect with the global research community. Using the official name helps ensure that your medical team is referencing the most current diagnostic criteria and associated clinical management protocols.

Next steps

• Consult with a clinical geneticist to review your specific microarray report and clarify whether your diagnosis is a deletion or a SHANK3 mutation.


• Join the Phelan-McDermid Syndrome Foundation or the DiseaseMaps.org community to connect with other families and share experiences.


• Request that your primary care physician use the term "Phelan-McDermid syndrome" in all referral letters to ensure consistency across your specialist team.


• Stay updated on clinical trials and research initiatives by monitoring the NIH GARD database.

Medical disclaimer: This information is for educational purposes only and does not constitute medical advice; please consult with a qualified healthcare professional regarding your specific diagnosis and treatment plan.

References

• Orphanet: Phelan-McDermid syndrome (ORPHA:635).


• NIH Genetic and Rare Diseases (GARD) Information Center: Phelan-McDermid syndrome.


• Online Mendelian Inheritance in Man (OMIM): Entry #606232.


• Phelan-McDermid Syndrome Foundation (pmsf.org).