Segmental Maternal UPD6 with Prenatal Growth Restriction

We report a child with segmental maternal uniparental isodisomy of chromosome 6, involving most of the long arm distal to 6q16, detected by SNP microarray. Clinical features include prenatal growth restriction, global developmental delay, and severe gastro-esophageal reflux disease. Maternal uniparental disomy (UPD) of chromosome 6 has previously been reported to cause intrauterine growth restriction. Paternal UPD of this chromosome is well known to cause transient neonatal diabetes mellitus. We discuss reported cases of maternal UPD of chromosome 6 and consider whether our patient's features may be due to disordered imprinting or unmasking of an autosomal recessive condition.