Prenatal manifestation and management of a mother and child affected by spondyloperipheral dysplasia with a C-propeptide mutation in COL2A1: case report

Abstract
It is not unusual for patients with “rare” conditions, such as skeletal dysplasias, to remain undiagnosed until
adulthood. In such cases, a pregnancy may unexpectedly reveal hidden problems and special needs. A 28 year old
primigravida was referred to us at 17 weeks for counselling with an undiagnosed skeletal dysplasia with specific
skeletal anomalies suggesting the collagen 2 disorder, spondyloperipheral dysplasia (SPD; MIM 156550).
She was counselled about the probability of dominant inheritance and was offered a prenatal diagnosis by
sonography. US examination at 17, 18 and 20 weeks revealed fetal macrocephaly, a narrow thorax, and shortening
and bowing of long bones. The parents elected to continue the pregnancy. At birth the baby showed severe
respiratory distress for four weeks which then resolved. Mutation analysis of both mother and child revealed a
hitherto undescribed heterozygous nonsense mutation in the C-propeptide coding region of COL2A1 confirming
the diagnosis of SPD while reinforcing the genotype-phenotype correlations between C-propeptide COL2A1
mutations and the SPD-Torrance spectrum. This case demonstrates the importance of a correct diagnosis even in
adulthood, enabling individuals affected by rare conditions to be made aware about recurrence and pregnancyassociated
risks, and potential complications in the newborn.