Pre‐ and postnatal growth failure with microcephaly due to two novel heterozygous IGF1R mutations and response to growth hormone treatment

• Published in: Acta Paediatrica Vol. 109; no. 10; pp. 2067 - 2074
• Main Authors: Gkourogianni, Alexandra, Andrade, Anenisia C., Jonsson, Björn‐Anders, Segerlund, Emma, Werner‐Sperker, Antje, Horemuzova, Eva, Dahlgren, Jovanna, Burstedt, Magnus, Nilsson, Ola
• Format: Journal Article
• Language: English
• Published: Norway Wiley Subscription Services, Inc 01-10-2020
• Subjects: Body Height; Child; Children; GH treatment; Growth Disorders - drug therapy; Growth Disorders - genetics; Growth Hormone - therapeutic use; Growth hormones; Heterozygote; Humans; Idiopathic short stature; IGF-I; IGF1R; IGFBP-3; Insulin; Insulin-Like Growth Factor I; Medicin och hälsovetenskap; Microcephaly; Microcephaly - drug therapy; Microcephaly - genetics; Mutation; Pediatrics; Pediatrik; Phenotypes; Physical growth; Receptor, IGF Type 1 - genetics; idiopathic short stature; IGF-I; IGFBP-3; GH treatment; IGF1R
• ISSN: 0803-5253; 1651-2227; 1651-2227
• DOI: 10.1111/apa.15218

Aim
To explore the phenotype and response to growth hormone in patients with heterozygous mutations in the insulin‐like growth factor I receptor gene (IGF1R).
Methods
Children with short stature, microcephaly, born SGA combined with biochemical sign of IGF‐I insensitivity were analysed for IGF1R mutations or deletions using Sanger sequencing and Multiple ligation‐dependent probe amplification analysis.
Results
In two families, a novel heterozygous non‐synonymous missense IGF1R variant was identified. In family 1, c.3364G > T, p.(Gly1122Cys) was found in the proband and co‐segregated perfectly with the phenotype in three generations. In family 2, a de novo variant c.3530G > A, p.(Arg1177His) was detected. Both variants were rare, not present in the GnomAD database. Three individuals carrying IGF1R mutations have received rhGH treatment. The average gain in height SDS during treatment was 0.42 (range: 0.26‐0.60) and 0.64 (range: 0.32‐0.86) after 1 and 2 years of treatment, respectively.
Conclusion
Our study presents two heterozygous IGF1R mutations causing pre‐ and postnatal growth failure and microcephaly and also indicates that individuals with heterozygous IGF1R mutations can respond to rhGH treatment. The findings highlight that sequencing of the IGF1R should be considered in children with microcephaly and short stature due to pre‐ and postnatal growth failure.