Endocrine Abstracts

Chromosome 17q12 deletion is rare. It results from the deletion of a piece of chromosome 17 in each cell. The most recognised phenotype of this mutation is a combination of kidney cysts and Maturity Onset Diabetes of the Young (MODY), which is also known as Renal Cysts and Diabetes syndrome (RCAD). RCAD is caused by a mutation in the gene encoding hepatocyte-nuclear-factor-1-beta (HNF1B) which is part of chromosome 17q12.

Introduction: In 1997 while studying the genetic background of a Japanese family who had MODY, HNF1B was first affiliated with MODY. However, further studies on this gene has shown that this mutation is linked to many other phenotypes including; renal problems, neurological problems abnormal liver function, genital tract malformations, hyperuricemia and hypomagnaseamia and others. However, intrauterine growth restriction (IUGR) is not a recognised phenotype. This report will discuss IUGR as a presentation of 17q12 deletion.

Case report: A 24-year-old primigravida mother was antenatally diagnosed to have IUGR. There were no risk factors for IUGR. Delivery was induced at 37+3 weeks of gestation in view of IUGR. The baby was born in a good condition with weight, length and head circumference plotting on 2nd centiles. Neonatal check was normal. In view of symmetrical IUGR, CGH array was checked which showed 17q12 deletion. Therefore, renal ultrasound was checked in addition to glucose, uric acid and magnesium. Her investigations were normal but renal ultrasound showed duplex left kidney. This baby is under follow up by paediatric consultant to monitor growth and development and associated abnormalities.

Conclusion: It is evident that this mutation is under-recognised and linked to many phenotypes, some of which might be life detrimental if not detected early, so earlier presenting features should be further explored. A very early clinical feature is suggested in our report, which is symmetrical IUGR of unknown aetiology. It suggests that if symmetrical IUGR of unknown aetiology, by itself, does not trigger the paediatrician to do further genetic tests, it should ideally be considered to be one of the presentations secondary to 17q12 mutations.