| Symbol
| SSDI
|
| Location
| Xp22.31
|
| Name
|
X-linked ichthyosis |
| Other name(s)
|
STS-deficiency, steroid sulfatase deficiency with ichthyosis |
| Corresponding gene
|
STS
|
| Other symbol(s)
| XLI
|
| Main clinical features
|
generalized scaling that usually begins soon after birth
asymptomatic corneal opacities
increased incidence of cryptorchidism
may be a risk factor for ADHD ( attention deficit hyperactivity disorder ) with predominantly inattentive symptoms (Kent 2008)
maternal failure to progress during labor
increased risk of ADHD, autism and social communication deficits |
| Genetic determination
| sex linked |
|
| genomic disorder |
| Prevalence
| 1/3000-1/1500 males
|
| Related entries
| DELXPM
|
| Function/system disorder
| dermatology |
| Type
| disease
|
| Gene mutation | Chromosome rearrangement | Effect | Comments |
|
|---|
| various types
|
| abnormal protein/loss of function
| ~10 percent of patients have point mutations or other intragenic mutations
| |
| deletion
| haploinsufficiency
| typically 1.5 Mb due to NAHR between the CRI-S232 low-copy repeat regions flanking the STS gene in 85-90 percent of cases
| |
| deletion
|
| larger deletions leading to contiguous gene syndrome
| |
| Remark(s)
|
most apparently sporadic affected males are due to maternally inherited deletions |
| Genotype/Phenotype correlations
|
larger deletions may be associated with mental retardation as part of a contiguous gene syndrome
large deletions encompassing STS and NLGN4 are at increased risk of developing autism and related disorders (Kent 2008) |