Genetics

Achondroplasia has an autosomal dominant pattern of inheritance. However, most cases are the result of a new mutation. There is full penetrance of the condition and little variation in expressivity.

The underlying defect involves fibroblast growth factor receptor 3 protein, on chromosome 4.

Diagnosis of this condition can be made by ultrasound in the second trimester.

Reference

1. Leiva-Gea A, Martos Lirio MF, Barreda Bonis AC, et al. Achondroplasia: Update on diagnosis, follow-up and treatment. An Pediatr (Engl Ed). 2022 Dec;97(6)