Question

Please DO NOT COPY from any website. UNIQUE UNIQUE.

Discussion :

The "Online Mendelian Inheritance in Man" website (www.omim.org) is a great source for information about human genes and genetic traits. Each entry has a unique six-digit number. Autosomal dominant traits have entries that start with a 1, autosomal recessive traits a 2, X-linked a 3, mitochondrial a 5, and specific genes have a number that starts with a 6. I would like you to research one genetic disorder and write a brief paragraph describing the disorder as well as the gene involved and the function of the gene product (if known). To make this first topic easy, I am including a list of choices with a link to the Genetics Home Reference page which describes the gene and the function of the gene product and the entry number to search for on www.omim.org. If you choose a topic from my list then you do not need to post the reference. However, if you would prefer to choose a disorder that is not on the list then you will need to list your reputable source (.org/.gov/.edu).

Here is the list: please write about number 11. Holoprosencephaly, link http://ghr.nlm.nih.gov/gene/SHH

11. Holoprosencephaly: http://ghr.nlm.nih.gov/gene/SHH; MIM 142945

Answer 1

SJOGREN-LARSSON SYNDROME; SLS (OMIM - 270200)

1)Autosomal recessive disease

Sjogren larsons syndrome is an inborn genetic disorder.It is one of the major cause of founder effect occured 600 years ago.This disease is characterized by scaly,dry skin, spastic movement in the legs and other nurological disorders like leukoencephalopathy (changes in white matter of brain), muscular dystrophy.People having this disorder unable to detoxify long chain fatty aldehyde molecules due to the mutation in gene ALDH3A2.This gene is responsible for the formationof enzyme fatty aldehyde dehydrogenase (FALDH) which break these fatty aldehydes into their respective alcohols but due to the mutation in ALDH3A2 there is an accumulation of fats occur within the skin.These accumulated fats interfear in formation of protective barrier to control water loss from skin which causes difficulty in maintaing moisture beneath epidermis which ultimatly leads to dry and scaly skin.

In brain, these accumulated fats results in disruption of myelin sheath covering of the nerve cellls.As a consequence efficient impulse transmission is haulted which is one of major cause of intellectual disability.

Reference-Sjögren-Larsson syndrome (PMID:8217559)