Intrauterine Growth Restriction and Hypertrophic Cardiomyopathy as Prenatal Ultrasound Findings in a Case of Leprechaunism.

Donohue syndrome (leprechaunism; OMIM *246200) is a rare and often lethal autosomal recessive disease caused by mutations in the INSR gene. We report the case of a 29-year-old pregnant woman, primigravida, who was referred at 33 weeks of gestation for severe intrauterine growth restriction (IUGR). Ultrasound examination found severe IUGR associated with an obstructive hypertrophic cardiomyopathy (HCM), confirmed postnatally. The newborn's blood glucose level fluctuated from fasting hypoglycemia to postprandial hyperglycemia. The infant was found to be homozygous for a novel missense pathogenic variant, c.632C>T (p.T211l), in exon 2 of the INSR gene, predicted to result in an abnormal insulin receptor. To our knowledge, this is the first report of leprechaunism being revealed by IUGR and HCM during the prenatal period. Clinicians should keep in mind that the association of these prenatal signs could indicate leprechaunism and specific early neonatal management could be proposed, in particular with recombinant human insulin-like growth factor-I.