A case report of recurrent achondroplasia in fetuses of normal parents

ABSTRACT Achondroplasia, a skeletal dysplasia has an incidence of 1 in 15000 to 1 in 30000 live births. It is inherited in an autosomal dominant manner. The occurrence of recurrent achondroplasia in babies born to normal parents is rare. The present case report is one such type. A female fetus of 27 weeks gestational age was brought to the Department of Anatomy, Karpaga Vinayaga Institute of Medical Sciences, Maduranthagam. There was frontal bossing of forehead, rhizomelic type of limb shortening with limitation of elbow extension in the fetus. The mother of the fetus, who is 26 years old, gave history of recurrence of such condition. Her first pregnancy was a twin pregnancy, conceived by natural methods, where one of the twins was a male baby who also had achondroplasia and died 2 hours after delivery. The other twin is a girl and the child has delayed developmental milestones. Her second pregnancy was uneventful. The present fetus under study is from her third pregnancy. Her marriage is of second degree consanguineous type. The age of her husband is 36 years old. Germinal mosaicism has been attributed for the causation of recurrent achondroplasia in children, whose parents are normal. 80% of a chondroplasia is due to a new mutation. Only 20% of achondroplasia is inherited. Increased paternal age is a risk factor for new mutations to occur. The other investigations of the case and the genetic analysis are described further in the article