What are the symptoms?
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). Less frequently, some children present with heart defects (such as a hole in the heart) or kidney defects, although these are usually not life-threatening. These are often the first noticeable symptoms and are what prompt families to start down the diagnostic journey.
As children grow, different symptoms develop. People with PMS typically have moderate to severe developmental and intellectual impairment, most do not develop functional language, and about 75% have been diagnosed with an Autism Spectrum Disorder. Behavioral issues may stem from autism (e.g., repetitive behaviors), from 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 develop seizures. Although seizures don’t appear to be a common symptom of PMS, those that occur can range from mild to severe.
Many parents report that their child does not seem to feel pain as most people do, but instead has a very high tolerance for pain. High pain tolerance in conjunction with communication issues can make it difficult for parents to know when their child has pain due to constipation, reflux, or other conditions that need to be treated. People with PMS also seem to sweat less than others, and are at risk of overheating. It’s very important that caregivers monitor carefully for injuries and overheating.
In spite of these medical and developmental issues, infants with PMS tend to be easily amused, and adults often have a sweet disposition.
You doctor may also talk to you about facial and body characteristics that are common in people with PMS, but don’t cause any medical problems. Common facial characteristics include dolichocephaly (a head shape that is longer than usual, from front to back), flat midface, wide brow, wide nasal bridge, deep-set eyes, full cheeks, puffy eyelids, long eyelashes, and bulbous nose. Large fleshy hands, dysplastic toenails, sacral dimple, and large, differently formed ears are frequently observed.
Thus far relatively few cases of PMS have been identified. Most people that have been identified are children because testing is usually done early in life and testing to detect submicroscopic deletions did not become commonly available until about 1998. As a result, most of our information about PMS is about children, and less is about the experiences of adults with PMS. We are working hard to engage our adult community members and promote the availability of testing to adults.