Monosomy 9p is also called 9p minus and Alfi’s syndrome. It is an extremely rare genetic disorder with an estimated 125 people with the condition in the US. The chromosome distortion that causes monosomy 9p concerns the ninth chromosome. People with this condition are missing part of their ninth chromosome. This deletion leads to a variety of conditions and complications.
Since the condition is so rare, there are few studies regarding it. What can be said about monosomy 9p is that the missing parts caus a number of symptoms to emerge, and that geneticists believe the deletion of the chromosome parts occurs very early in the fetal growth process, and has no identifiable cause.
People with monosomy 9p are likely to have distorted facial features, very similar to those children with Down syndrome. The nose is normally flat, with flared out nostrils, the eyelid folds slant upward, and the forehead may be wide. As with Down syndrome, stature tends to be short. Mild to severe mental retardation is usually present, and children with this condition are characterized as being extremely friendly and trusting of strangers. Unlike Down syndrome, children with the condition often have smaller than normal heads, called microcephaly.
Other medical conditions associated with monosomy 9p include microgenitalia; that is, very small, sometimes almost absent appearing genitals. Gender identification in infants can be complicated. People with this condition may also have other health problems, which can affect survival and longevity. Many affected by the condition have congenital heart defects, and some have esophageal defects. Other abnormalities of growth, organ placement or development, and cognitive development may be present.
The severity of monosomy 9p greatly influences how much additional care will be needed for a child with this condition. Some are able to live fairly normal lives, especially when cognitive impairment is minor and few structural organ defects exist. For severe cases, the condition may correspond to a short lifespan and requires continual care from parents or caretakers.
There are a variety of groups that can help provide more information and help including the March of Dimes, the Children’s Craniofacial Association, and Chromosome Deletion Outreach.