In humans, the sox7 and TNKS genes are located on the short arm of chromosome 8
ID: 57283 • Letter: I
Question
In humans, the sox7 and TNKS genes are located on the short arm of chromosome 8 between two direct repeats in a region called "8p23.1". Children born with "8p23.1 deletion syndome" inherited a deletion of the sox 7 and TNKS genes from one parent. Children born with "8p23.1 duplication syndrome" inherited an extra copy of both the sox7 and TNKS genes from one parent. Both syndromes cause developmental problems. Starting from the above diagram of the "8p23.1" region, breifly explain how these duplication and deltion syndromes could arise.
Explanation / Answer
8p23.1 causes the deletion syndrome by deletion of certain nucelotides between the coding regions sox7 and TNKS genes resulting genetical disorders associated with mental disabilities arouse from dysfunctional olfactory receptor/defensin repeats (ORDRs).
Duplication of 8p23.1 may involve copy number changes of the adjacent olfactory receptor/defensin repeats (ORDRs) that have been associated with a number of traits. About 3.68 Mb size gene repeats between the distal and proximal olfactory receptor/defensin repeats (ORDRs) at the telomeric and centromeric ends of band 8p23.1 are observed. The copy number of the adjacent repeats may also be altered and occasional duplications involve limited regions beyond the repeats.