HOMOZYGOUS ACHONDROPLASIA

This is the lethal form of achondroplasia due to the respiratory complications that arise due to the thoracic constriction that is present (1).

• Risk of homozygosity if one parent is affected is low (1:50,000 births or 0.002%). Homozygosity occurs due to a spontaneous mutation of the unaffected gene from the non achondroplastic parent.
• Risk of homozygosity increases to 25% when both parents have achondroplasia.

REFERENCES

1. Alterman K, Welch JP, Taylor PG. Presumed homozygous achondroplasia: a review and report of a further case. Pathol Res Pract 1983;178:27-39.