Achondrplaisa is a disease characterized by short stature (short stature is when the height is low as compared to the normal height of a person). This short stature is due to abnormal growth of bones, caused by defective formation of cartilage. Jyoti Amge, a 15-year-old girl from India, broke the world record for the shortest person on earth. Diagnosed with achondroplasia, she is 23 inches (58 cm) tall, and weighs 11 lbs (5 kg). Several conditions in heriditary disorders coincide with achondrplasia like osteogenesis imperfecta, multiple epiphyseal dysplasia tarda, achondrogenesis, osteopetrosis, and thanatophoric dysplasia. The incidence of this condition is about 1 in very 25,000 persons.

The basic cause behind this disease is mutation in the fibroblast growth factor receptor gene called FGFR 3, which leads to abnormaility in the formation of cartilage and hence this results in shotrened bones; this is due to the cartilage in the bone not allowing its normal growth and hence they get shortened - resulting in the short stature of the affected individual. This disease is autosomal dominant, i.e, only one copy of a mutant gene is necessary for the disease to occur. The presence of mutant allele on both chromosomes will be fatal and the baby willl die just after birth. Studies show that there is some defect in the gene during spermatogenesis which leads to achondrplasia in child. During oogenesis there is some mechanism which hinders the the mutation in them. 99% of the times, the disease occurs due to the mutation from G->A in nucleotide 1138 of gene FGRF3, while only 1% occurs due to G->C in nucleotide 138 of gene FGRF3.

Defects in genes cannot be prevented.