SNP Shot: Genomic Insights

Isolated hyperchlorhidrosis is a condition where individuals lose an abnormally high amount of salt (sodium chloride, or NaCl) through their sweat. The term "hyperchlorhidrosis" specifically indicates elevated chloride levels in the sweat, although both sodium and chloride are lost in excess. This excessive salt loss leads to lower than normal sodium levels in the body's fluids, a condition called hyponatremia. Infants with isolated hyperchlorhidrosis often experience episodes of dehydration accompanied by low blood sodium (hyponatremic dehydration), sometimes requiring hospital care. These episodes are frequently triggered by mild illnesses involving vomiting or diarrhea. Affected infants may also exhibit poor feeding and struggle to grow and gain weight as expected (failure to thrive). However, growth typically normalizes by early childhood, although the abnormal salt loss persists. These individuals remain susceptible to dangerous hyponatremia during periods of excessive sweating, such as in hot weather or during exercise.

Although hyperchlorhidrosis can be a symptom of other conditions like cystic fibrosis, individuals with isolated hyperchlorhidrosis do not exhibit the other symptoms associated with those conditions.

Inheritance:

Isolated hyperchlorhidrosis follows an autosomal recessive inheritance pattern. This means that both copies of the responsible gene in each cell must have mutations for the condition to manifest. Individuals with autosomal recessive conditions inherit one mutated copy of the gene from each parent. The parents, who each carry only one mutated copy, typically do not show any signs or symptoms of the condition themselves.