From the Guidelines
Yes, certain forms of ichthyosis are more prevalent among people who mate with close relatives due to the increased risk of inheriting rare recessive genes. Ichthyosis refers to a group of genetic skin disorders characterized by dry, thickened, scaly skin, as discussed in the European guidelines of care for congenital ichthyoses 1. Many types of ichthyosis are inherited in an autosomal recessive pattern, meaning a person needs to inherit two copies of the mutated gene (one from each parent) to develop the condition. When close relatives have children together, there's a higher chance that both parents carry the same rare recessive genes, increasing the risk of their children inheriting two copies of these genes. Some key points to consider include:
- Autosomal recessive congenital ichthyosis (ARCI) shows higher prevalence in populations with higher rates of consanguinity, as noted in the guidelines 1
- The increased risk occurs because close relatives share a greater percentage of their genetic material compared to unrelated individuals
- For families with a history of ichthyosis or those in consanguineous relationships, genetic counseling before conception can help assess risks and provide information about inheritance patterns and available testing options, as recommended in the guidelines 1
- The guidelines also highlight the importance of managing complications and particularities of CI, which can have a major effect on quality of life 1
- Lifelong treatment is often necessary, and various symptomatic treatment options exist, although there are no curative therapies currently available 1
From the Research
Prevalence of Ichthyosis among People who Mate with Close Relatives
- There is no direct evidence to suggest that ichthyosis is prevalent among people who mate with close relatives, as the provided studies do not specifically address this topic.
- However, some forms of ichthyosis are inherited in an autosomal recessive pattern, which means that they can be more common in populations where consanguineous marriages are prevalent 2.
- For example, congenital autosomal recessive ichthyosis (CARI) and Sjögren-Larsson syndrome are autosomal recessive disorders that can be caused by mutations in specific genes 2, 3.
- Additionally, Netherton's syndrome is an autosomal recessive disorder characterized by ichthyosis, hair shaft abnormality, and atopy, which may be more common in populations with a high rate of consanguineous marriages 2.
- However, more research is needed to determine the specific relationship between ichthyosis and consanguineous marriages, as the current evidence is limited and indirect.