Loss of function mutations in KAL1, including whole or partial gene deletions, cause Kallmann syndrome in males. Female carriers are typically unaffected. See GeneReviews.
The loss-of-function and triplosensitivity ratings for genes on the X chromosome are made in the context of a male genome to account for the effects of hemizygous duplications or nullizygous deletions. In contrast, disruption of some genes on the X chromosome causes male lethality and the ratings of dosage sensitivity instead take into account the phenotype in female individuals. Factors that may affect the severity of phenotypes associated with X-linked disorders include the presence of variable copies of the X chromosome (i.e. 47,XXY or 45,X) and skewed X-inactivation in females.
There have been no focal duplications of KAL1 reported. Mencarelli et al (2008) report a female patient who had autism, skeletal defects, short stature, facial asymmetry, and heart valve defects. She had a 0.8 Mb duplication that included KAL1 and other genes and that was inherited from a healthy father (PMID: 18657637).
The loss-of-function and triplosensitivity ratings for genes on the X chromosome are made in the context of a male genome to account for the effects of hemizygous duplications or nullizygous deletions. In contrast, disruption of some genes on the X chromosome causes male lethality and the ratings of dosage sensitivity instead take into account the phenotype in female individuals. Factors that may affect the severity of phenotypes associated with X-linked disorders include the presence of variable copies of the X chromosome (i.e. 47,XXY or 45,X) and skewed X-inactivation in females.