sex linked inheritance

Sex Linked Inheritance/ X - linked trait

X-linked is a trait where gene is located on X- chromosome.

Sex-linked inheritance disease

Sex linked disease are inherited through one of sex chromosome, which are X and Y chromosome is called sex- linked inheritance.

Sex linked is trait in which gene is located on sex chromosome.

Inheritance of those genes which are present on X chromosome.

Autosomes (1-22) pair

Allosomal (23rd); sex chromosome XY, XX

Sex (X) linked Document Inheritance

X- linked Dominant Inheritance disorders are;

1. Rett syndrome (affecting brain development in girl).

2. X-linked hypophosphatemia; low level of phosphate in blood

3. Incontinentia pigmenti; affects skin

4. Aicardi syndrome; interfere with formation of corpus collosum.

5. X-linked dominant porphyria (abnormal sensitivity to sun)

6. Fragile X- syndrome; causing intellectual disability

Sex (X) link Recessive Disorders

Sex (X) link Recessive Disorders are;

1. Haemophilia A, B

2. Diabetes insipidus

3. Red-green blindness

4. Duchenne muscular dystrophy; progressive muscular weakness 

5. X-linked ichthyosis

6. Becker muscular dystrophy; degenerative disease primarily affecting voluntary muscle.

For example;

Hemophilia A and B; X - Link Recessive Inheritance

XX (carrier Mother)    XY father with haemophilia)

XX; carrier daughter

XY; Normal son

XX; daughter with haemophilia

XY; son with haemophilia

For example, X linked Dominance inheritance

Affected father (XY)   Unaffected mother (XX)

XX; affected daughter

XX; affected daughter

YX; Unaffected son

YX; Unaffected son

Affected Mother (XX)    unaffected father (XY)

XX; unaffected daughter

XY; unaffected son

XX; affected daughter

XY; affected son