X-Nico

5 unusual facts about X chromosome


Andrea Prader

Females are not affected by the condition, however due to linkage of heredity with the X chromosome, they are thought to be genetic carriers.

Jozef Gécz

Dr Jozef Gécz is a senior researcher at The University of Adelaide studying the various mutations of a small part of the X chromosome that lead to mental retardation.

Lesser kudu

But unlike other tragelaphids, the X chromosome and Y chromosome are compound and fused with autosomes from ancestors having a greater chromosome number.

MAGEA12

The MAGEA genes are clustered at chromosomal location Xq28.

X chromosome

It was first noted that the X chromosome was special in 1890 by Hermann Henking in Leipzig.


Amelogenin

Differences between the X chromosome and Y chromosome versions of the amelogenin gene (AMELX and AMELY respectively) enable it to be used in sex determination of unknown human samples.

The amelogenin gene has been most widely studied in humans, where it is a single copy gene, located on the X and Y chromosomes at Xp22.1-Xp22.3 and Yp 11.2 5.

Non-coding RNA

Xist (X-inactive-specific transcript) is a long ncRNA gene on the X chromosome of the placental mammals that acts as major effector of the X chromosome inactivation process forming Barr bodies.

PCDHY

PCDH11X located on the X chromosome is common, in both sexes, to humans and our nearest relative, the chimpanzee; however, PCDH11Y located on the Y chromosome, is unique to men.

X-linked agammaglobulinemia

XLA is caused by a mutation on the X chromosome of a single gene identified in 1993 which produces an enzyme known as Bruton's tyrosine kinase, or Btk.

Xq28

One study showed weak linkage to the Xq28 region, whereas a second in 1999 studying Canadian material consisting of 52 pairs of gay brothers found no statistically significant linkage in alleles and haplotypes and concluded against an X-linked male homosexuality gene.


see also

DDX3Y

This gene encodes a DEAD box protein, and it has a homolog on the X chromosome (DDX3X).

Duchenne

Duchenne muscular dystrophy, a severe recessive X-chromosome linked form of muscular dystrophy

Ernest Beutler

A new colleague at the City of Hope and ultimately a lifelong friend, Susumu Ohno had recently demonstrated that the histologically observable Barr body present in the nuclei of mammalian female cells was a hyperchromatic X chromosome.

Inactivation

X-inactivation, also called lyonization, a process by which one of the two copies of the x chromosome present in female mammals is inactivated

Smith–Fineman–Myers syndrome

Some patients with SFMS have been founded to have a mutation of the gene in the ATRX on the X chromosome, also known as the Xq13 location.

Susumu Ohno

He also discovered in 1956 that the Barr body of mammalian female nuclei was in fact a condensed X chromosome.