By: Reagan O’Reilly and Isaiah Barnes Cri-du-chat By: Reagan O’Reilly and Isaiah Barnes

What is Cri-du-chat? Cri-du-chat also know as 5p- is a very rare genetic disorder that is due to chromosomes being deleted It affects about 1 in 20,000 - 50,000 births across the world It is more common in females by about a 4:3 ratio

Information Cri-du-chat got its name from the cry of babies who were affected by it, it sounded like a kitten meowing due to problems with vocal cords. About 1/3 of the babies lost their cry by the age of 2 Some symptoms include: low weight, a small head, wide eyes, speech disorders, different facial features

Genetic Changes Cri-du-chat is caused by the short end arm of chromosome 5 (the pair inherited by both parents) being deleted Chromosome 5 holds about 181 million DNA pairs, about 6% of the DNA in cells How much is deleted varies among each person Larger deletions result in more intellectual disabilities than smaller deletions

Treatment Right now there is no specific treatment for cri-du-chat, at birth it can be diagnosed by analyzing DNA The cat like cry is a key feature for the diagnosis of the syndrome Kids with this syndrome will usually need lots of support from parents, doctors, and educations professionals to make sure they get a proper education and live normal lives

Is cri-du-chat inherited? No, it is not inherited at all The chromosome deletion usually occurs at a random time during the sperm or egg creation or at early fetus development. About 10% of people with cri-du-chat inherit the chromosome with the deleted segment from an unaffected parent. In this case the parent has a chromosomal rearrangement called balanced translocation where no genetic material is gained or lost. They usually do not cause medical problems but they can become unbalanced and be passed on to the next generation, in which the small strand is deleted.

Genotype/Phenotype A study for genotype/phenotype correlation was carried out on 80 patients The results confirmed that the deletion was key for the symptoms of cri-du-chat but the size of deletion varied among patients, 62 of the patients suffered terminal deletion while some had severe and others only partial deletion. The differences between them was severe

Works cited URL https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1574300/ Website Title National Human Genome Research Institute (NHGRI) Article Title Learning About Cri du Chat Date Accessed May 04, 2018 URL https://ghr.nlm.nih.gov/chromosome/5#conditions Website Title U.S. National Library of Medicine Article Title Chromosome 5 - Genetics Home Reference URL https://ghr.nlm.nih.gov/condition/cri-du-chat-syndrome# Article Title Cri-du-chat syndrome - Genetics Home Reference URL https://en.wikipedia.org/wiki/Cri_du_chat_syndrome Website Title Wikipedia Article Title Cri du chat syndrome Date Published May 03, 2018 URL https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1574300/ Website Title Advances in pediatrics. Publication Year 2006 Date Accessed May 04, 2018