Expert Reviewed By: Dr. Brandon Colby MD
Autosomal recessive hypotrichosis with woolly hair (ARHWH) is a rare genetic disorder that affects the hair and, in some cases, the nails. This condition is characterized by sparse, curly, and fragile hair that is prone to breakage. In this article, we will dive deep into understanding the genetics behind this disorder, the diagnostic process, and how genetic testing can be helpful for individuals and families affected by ARHWH.
Understanding the Genetics of ARHWH
ARHWH is caused by mutations in specific genes, such as the KRT25, LIPH, and KRT74 genes. These genes are responsible for producing proteins that play crucial roles in the structure and function of hair and nails. When these genes are mutated, the resulting proteins are unable to function properly, leading to the characteristic features of ARHWH.
KRT25 Gene Mutation
A study published in the Journal of Investigative Dermatology identified a previously unreported missense mutation in the KRT25 gene that causes ARHWH. This gene is expressed in hair follicles and is essential for the proper formation of hair shafts. The mutation results in the production of an abnormal keratin protein, which leads to the hair abnormalities seen in individuals with this form of ARHWH.
LIPH Gene Mutation
Another study explored the potential of botanical extracts to improve ARHWH caused by LIPH gene mutations. The LIPH gene is involved in the production of a lipid molecule that is important for hair growth. Mutations in this gene can result in hair abnormalities, such as those seen in ARHWH.
KRT74 Gene Mutation
A study published in PLOS ONE showed that homozygosity for a KRT74 missense variant may be associated with autosomal recessive pure hair and nail ectodermal dysplasia, which is a related disorder with overlapping features. This expands the phenotypic spectrum of KRT74 mutations and highlights the importance of understanding the genetics behind these rare conditions.
Diagnosing ARHWH
Diagnosis of ARHWH typically begins with a thorough examination of the affected individual's hair and nails, as well as a detailed review of their medical and family history. In some cases, a skin biopsy may be performed to further investigate the hair follicles and confirm the diagnosis. However, genetic testing is the most definitive way to diagnose ARHWH and identify the specific gene mutation responsible for the condition.
Using Genetic Testing for ARHWH
Genetic testing can be incredibly helpful for individuals and families affected by ARHWH. It can provide valuable information about the specific gene mutation causing the disorder, which can aid in diagnosis, guide treatment options, and inform family planning decisions.
Guiding Treatment Options
A clinical trial evaluated the effectiveness of topical minoxidil in treating hypotrichosis in patients with ARHWH carrying LIPH pathogenic variants. Genetic testing can help identify patients who may benefit from this treatment, allowing for a more targeted and personalized approach to managing the condition.
Informing Family Planning Decisions
Knowing the specific gene mutation responsible for ARHWH can provide valuable information for family planning. Couples who are carriers of the mutated gene may choose to undergo genetic counseling to better understand the risks of passing the condition on to their children and explore their reproductive options.
Connecting with Others
Genetic testing can also help individuals with ARHWH connect with others who share the same condition. This can provide a valuable support network for individuals and families affected by this rare disorder, as they can share experiences, advice, and encouragement.
In conclusion, understanding the genetics behind autosomal recessive hypotrichosis with woolly hair is crucial for diagnosing and managing this rare condition. Genetic testing can provide valuable information that can guide treatment options, inform family planning decisions, and help individuals connect with others who share their experiences.
About The Expert Reviewer
Dr. Brandon Colby MD is a US physician specializing in the personalized prevention of disease through the use of genomic technologies. He’s an expert in genetic testing, genetic analysis, and precision medicine. Dr. Colby is also the Founder of and the author of Outsmart Your Genes.
Dr. Colby holds an MD from the Mount Sinai School of Medicine, an MBA from Stanford University’s Graduate School of Business, and a degree in Genetics with Honors from the University of Michigan. He is an Affiliate Specialist of the American College of Medical Genetics and Genomics (ACMG), an Associate of the American College of Preventive Medicine (ACPM), and a member of the National Society of Genetic Counselors (NSGC)