What is a potential consequence of a homozygous condition of achondroplasia?

A homozygous condition of achondroplasia can lead to a lethal condition due to the nature of the genetic mutation associated with this disorder. Achondroplasia is primarily caused by a mutation in the FGFR3 gene, which affects bone growth and results in a form of skeletal dysplasia characterized by disproportionate short stature and specific skeletal abnormalities.

In cases where a person inherits two copies of the mutated gene (homozygous condition), the outcome typically results in a significantly more severe phenotype than when only one copy of the mutation is present (heterozygous condition). Most individuals with homozygous achondroplasia do not survive to birth or die shortly after birth due to complications that arise from the severe skeletal abnormalities, such as respiratory issues or other organ malfunctions.

In contrast, individuals with the heterozygous condition usually present with typical features of achondroplasia but can lead healthy lives. Other options, such as severe disability or delayed development, may be relevant to the heterozygous condition but do not accurately capture the typical outcome of being homozygous for the achondroplasia mutation. Normal growth is not a characteristic of either condition due to the inherent genetic issues that affect bone development.