Sunday, July 31, 2016
Inherited Disorders and Birth Defects
Chromosome 4 missing
My 3 week old niece has just been diagnosed as having chromosome 4 missing, apparently a very rare condition. Early hearing tests have shown that she is deaf; can you tell us if there are any other problems she might face?
Most likely the problem is that your niece is missing a part of one of her chromosome 4. I do not know of babies being born that are missing an entire chromosome 4 - those pregnancies would miscarry.
The type of problems you niece may have will depend on what piece of chromosome 4 is missing and how much is missing. In general, babies with a deletion (missing a part) of chromosome 4 have problems in growth - are usually small, often have small heads, may have hypotonia - their muscle tone is very low, can have deafness or other congenital problems such as a congenital heart defect or other birth defect.
Most children with a missing part of a chromosome including chromosome 4 have mental retardation. The extent of the mental retardation (how severe it is) is variable and depends on the individual child.
I would recommend that your cousin talk to a geneticist or genetic counselor to obtain specific information about this chromosome abnormality. They should be very helpful. He or she can locate a genetics center by contacting the National Society of Genetic Counselors Resource Link at the web site below.
Anne Matthews, RN, PhD
Associate Professor of Genetics
School of Medicine
Case Western Reserve University