What is the inheritance pattern for Vitamin D resistant (hypophosphatemic) rickets?

Vitamin D resistant rickets, also known as hypophosphatemic rickets, is characterized by a defect in the renal tubular reabsorption of phosphate, which leads to hypophosphatemia and subsequent rickets. The condition exhibits an X-linked dominant inheritance pattern. This means that the gene associated with the disorder is located on the X chromosome, and one copy of the mutated gene in females, or a single copy in males (who have only one X chromosome), is sufficient to cause the disease.

In X-linked dominant conditions, affected individuals can pass the gene to their offspring, with each child having a 50% chance of inheriting the disorder. Males typically have a more severe presentation due to having only one X chromosome, whereas females may exhibit milder symptoms because they have a second, potentially normal X chromosome that could partially compensate for the defective gene.

Understanding the inheritance pattern is crucial for genetic counseling, as it impacts familial recurrence risks, and helps in the management and treatment strategies for affected individuals. This knowledge also assists healthcare providers in monitoring family members for potential signs and symptoms of the condition.