Neonatal punctate calcifications associated with maternal mixed connective tissue disorder (MCTD)

Chondrodysplasia punctate (CDP) is a rare group of disorders with both genetic and non-genetic underlying aetiologies. The genetic causes associated with CDP include peroxisomal disorders, type two mucolipidosis, type 3 mucopolysaccharidosis, GM1 gangliosidosis and chromosomal disorders. Peroxisomal disorders include deficiency of dihydroxyacetone phosphate acyltransferase, encoded by GNPAT, deficiency of the peroxisomal enzyme alkyl-dihydroxyacetone phosphate synthase, encoded by AGPS and Zellweger syndrome. The chromosomal disorders include Turner syndrome, trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome) and trisomy 9. Among non-genetic causes, teratogen exposure like warfarin and acenocoumarol is well known but for the past few years cases have been reported with maternal autoimmune disease mainly systemic lupus erythematosus and rarely with mixed connective tissue disorder (MCTD). However, the exact mechanism for the occurrence of CDP in MCTD is still unknown. We present here a 35-week appropriate for gestational age baby born to a second gravid mother, a known case of MCTD on treatment with hydroxychloroquine. The baby had mid-facial hypoplasia and bilateral talar region punctuate calcification suggestive of chondrodysplasia punctata. Global data on such cases are very scant. Further research work is needed to explore the association of specific antibody titre with the occurrence of such condition in maternal autoimmune disease.