About PMS
ABOUT PMS
What is Phelan-McDermid Syndrome?
Phelan-McDermid syndrome (PMS) is a rare genetic disorder caused by a deletion of the distal long arm of chromosome 22 or by a pathogenic variant in the SHANK3 gene.
What Are The Symptoms?
As is the case with many rare conditions, families may come across several different descriptions of this syndrome based on varying genetic descriptions and varying symptoms. Because the genetic changes vary, Phelan-McDermid syndrome (PMS) symptoms vary too, and can cause a wide range of medical, intellectual, and behavioral challenges. People who have PMS often show symptoms in very early childhood, sometimes at birth and within the first six months of life. They often have hypotonia (low or weak muscle tone) and developmental delay (not achieving developmental milestones such as rolling over, sitting up, walking, or talking on time).
People with PMS typically have moderate to severe developmental and intellectual impairment, most do not develop functional language, and approximately 75% have been diagnosed with an Autism Spectrum Disorder. Behavioral issues may stem from autism (e.g., repetitive behaviors), poor communications skills, or from an unknown origin. Sleep disorders are commonly reported, as are difficulties with toilet training, and problems with eating. About 40% of people with PMS develop seizures that range from mild to severe. People with PMS have a very high pain tolerance and also tend to sweat less than others which puts them at risk of overheating.
75%
the estimated percentage of people with Phelan-McDermid Syndrome (PMS) who have been diagnosed with an Autism Spectrum Disorder
