The homozygous mutation of the IGF1R is associated with severe IUGR, dysmorphic features, and insulin resistance, while both parents were asymptomatic heterozygous carriers of the same mutation.
A novel heterozygous IGF1R missense mutation in exon 7 (c.A1549T, p.Y487F) was identified in a short-statured girl with severe prenatal growth retardation and microcephaly.
We identified a family bearing a new heterozygous missense mutation at the L2 domain of IGF-IR (R431L) through an 8-year-old girl and her mother, both born with intrauterine growth retardation.
Only the second compound heterozygous IGF1R mutations to be identified, the p.E121K/E234K variant is the cause of intrauterine growth retardation and the most severe postnatal growth failure described to date in a patient with IGF1R defects.
Clinical and functional characteristics of a novel heterozygous mutation of the IGF1R gene and IGF1R haploinsufficiency due to terminal 15q26.2->qter deletion in patients with intrauterine growth retardation and postnatal catch-up growth failure.
Microscopically visible heterozygous terminal 15q deletions encompassing the IGF1R gene are rare and usually associated with intrauterine growth retardation and short stature.
Since deletion of IGF1Rhas repeatedly been reported to be associated with IUGR, it is tempting to speculate that the dosage of IGF1R may have determined growth in these children.
The increase in the transcription of IGF2 and IGF1R in IUGR term placentas may represent a counter regulatory mechanism in response to the growth retardation.
It is interesting to speculate that the severe IUGR and postnatal growth deficiency of our patient and other patients with similar chromosome 15 deletions are related to the loss of an IGF1R gene copy which may lead to an abnormal number and/or structure of the receptors.