Our son Salvador has Phelan-McDermid syndrome. He is missing genes on his 22nd chromosome — this is also known as 22q13 Deletion Syndrome (spoken as twenty two q one three). The Phelan-McDermid Syndrome microdeletion found in our son is rarely uncovered by typical genetic screening, therefore a fluorescence in situ hybridization, or FISH, test is recommended to confirm the diagnosis.
Recent work indicates Phelan-McDermid Syndrome may also be caused by errors in a single gene (SHANK3/PROSAP2) in the q13.3 region. Errors on the same gene have been associated with Autism Spectrum Disorder (ASD).
PMS is characterized by general hypotonia, absent to delayed speech, and global developmental delays. There are approximately 600 reported cases of Phelan-McDermid Syndrome worldwide.
Although Salvador looks normal in the outside, there is a lot going on in the inside. PMS does not allow him to speak but it does allow him to be the sweetest thing on the world. He may be one in 10 million but to us he is number 1!