Greenville Hosts the 2008 22q13 Deletion Foundation Conference

You may have seen the WYFF News at 6:00 coverage highlighting this international conference in Greenville. This was the sixth biennial gathering of families from around the world, meeting for support, education, and genetic evaluations for their children who have a rare genetic disorder called 22q13 deletion syndrome or Phelan-McDermid syndrome.

In this condition there is a small piece missing from one of the chromosomes 22. This deletion is detected through chromosome analysis and confirmed through a more precise chromosome test called FISH.

Humans normally have a total number of 46 chromosomes or 23 pairs, with one member of each pair coming from each parent. Chromosome 22 is one of the smallest chromosomes and was the first chromosome to be fully sequenced in the Human Genome Project. It is estimated that chromosome 22 contains 500-800 genes.

Physical features of Phelan-McDermid include poor muscle tone in the newborn period, severe developmental delays, absent or significant speech delay, long eye lashes, and large, fleshy hands. Many of the behavioral findings are similar to those in autism spectrum disorders including repetitive or stereotypical movements and decreased social interactions. The incidence of the condition is not known due to lack of clinical recognition and consequently under-diagnosis. In most families, the deletion has occurred only in one family member.

Patients with this syndrome are advised to receive routine examinations by their family physician. Early intervention therapies proving beneficial are physical therapy, communication therapies, exercise and sports activities, and music therapy. Disabilities are lifelong with individuals requiring supervision and care.

For more information on 22q13 deletion syndrome or Phelan-McDermid syndrome, visit the Foundation's website at www.22q13.org/home.html. Dr. Katy C. Phelan, who first identified this genetic condition, is the former director of the clinical cytogenetics laboratory at the Greenwood Genetic Center.