Intrauterine Twin Discordancy and Partial Postnatal Catch-up Growth in a Girl with a Pathogenic IGF1R Mutation

• Main Authors: Paula Ocaranza, Monique Losekoot, Marie J. E. Walenkamp, Christiaan De Bruin, Jan M. Wit, Veronica Mericq
• Format: Article
• Language: English
• Published: Galenos Yayincilik 2019-09-01
• Series: JCRPE
• Subjects: Insulin-like growth factor type-1; insulin-like growth factor type-1 receptor; small for gestational age; postnatal growth; intrauterine discordancy
• Online Access: http://www.jcrpe.org/archives/archive-detail/article-preview/ntrauterine-twin-discordancy-and-partial-postnatal/25619
• ISSN: 1308-5727; 1308-5735

Objective:Insulin like growth factors-1 (IGF-1) is essential for normal in utero and postnatal human growth. It mediates its effects through the IGF-1 receptor (IGF1R), a widely expressed cell surface tyrosine kinase receptor. The aim of the study was to analyze pre- and post-natal growth, clinical features and laboratory findings in a small for gestational age (SGA) girl in whom discordant postnatal growth persisted and her appropriate for gestational age (AGA) brother.Methods:A girl born with a low weight and length [-2.3 and -2.4 standard deviation (SD) score (SDS), respectively] but borderline low head circumference (-1.6 SD) presented with a height of -1.7 SDS, in contrast to a normal height twin brother (0.0 SDS). IGF-1 resistance was suspected because of elevated serum IGF-1 levels.Results:Sequencing revealed the presence of a previously described pathogenic heterozygous mutation (p.Glu1050Lys) in the SGA girl which was not present in the parents nor in the AGA twin brother.Conclusion:The pathogenic IGF1R mutation in this girl led to intrauterine growth retardation followed by partial postnatal catch-up growth. Height in mid-childhood was in the lower half of the reference range, but still 1.7 SD shorter than her twin brother.