Wednesday, 15 October 2014

IP1 & IP2 ?

Diagnosing any rare disease is hard enough but when there is confusion between two completely different rare diseases that once carried almost the same name and the information is still available on the internet and in medical journals, it just causes added unnecessary confusion and delayed diagnosis.

IP1 was formally - Hypomelanosis of ITO
IP2 was formally - Incontinentia Pigmenti

The most common misdiagnosis as it clinically
presents like IP and can cause many of the affects like IP is
Hypomelanosis of ITO; HMI #300337. Hypomelanosis of ITO (formally IP1) is located at Xp11 and is in Fact NOT IP. Hypomelanosis of ITO at times is misunderstood by doctors because of a "mis-assignment of a wrong diagnosis" which has recently been corrected.

Hypomelanosis of ITO is located at Xp11
Xp11 is located on the short arm of the X chromosome

Incontinentia Pigmenti is located at Xq28.
Xq28 is located on the long arm of the X chromosome

Now that the gene responsible for Incontinentia Pigmenti has been characterized, diagnosis can be supplemented with molecular testing. However, diagnosis of new patients is normally carried out using clinical criteria. If the classic rash is present in a newborn, the diagnosis is fairly straightforward, but it can be more difficult when the rash is mild, when not all the stages are present, or when an adult is seen and the lesions have faded. A skin biopsy that shows the presence of "loose" melanin (the brown-black skin pigment) in the dermis of the skin confirms the diagnosis, in the appropriate clinical setting. When there is little or no skin involvement, IP may be assumed to be the diagnosis in individuals "at risk" for the disease if they have other features such as tooth abnormalities, missing patches of hair, or overgrowth and scarring of the retinal blood vessels. Such an "at risk" individual would be a woman with two (or more) affected daughters, the daughter of an affected woman, or the sister of an affected woman who herself has had the miscarriage of more than one male fetus.

The only way to map the IP mutation at Xq28 is to have molecular testing. Having this mapping completed is imperative for future family testing and for IP to NOT be overlooked again within a Family Line.

OMIM Entry - Incontinentia Pigmenti; IP #308300 -

OMIM Entry - Hypomelanosis of ITO; HMI #300337 -

October is IP awareness month... Spread the word... spread awareness!

No comments:

Post a Comment