Insight into Insulin-like Growth Factor-1 Receptor (IGF-1R) gene mutations: Implications for growth disorders and treatment: A review of the literature and case report

Abstract

Background: Insulin-like Growth Factor -1 Receptor (IGF-1R) and its ligand, IGF-1, are crucial for human tissue growth and development. Mutations in IGF-1R and, to a lesser extent, IGF-1 genes lead to diverse growth disorders, characterized by intrauterine growth retardation and postnatal growth challenges. Case report: We present a case of a 6-year-old girl with speech and mild cognitive delays, exhibiting normal motor skills, no neurological issues, and standard vital signs. Her growth parameters indicated significant retardation, with a height standard deviation score (Ht-SDS) of -2 and an IGF-1 level of +1.8 SDS, normal thyroid function and delayed bone age. Genetic analysis identified a 3335 mbp interstitial loss in 15q26.1, encompassing the IGF-1R gene, critical for growth and development. Literature review: Analysis of 34 papers provided insight into the genetic complexities of IGF-1R and IGF-1 mutations. Studies ranged from familial cases to cohort studies, uncovering mutations including missense mutations, deletions, and copy number variations (CNVs), each associated with unique growth disorder phenotypes. Advances in diagnostic techniques like multiplex ligation-dependent probe amplification (MLPA) and whole exome sequencing (WES) have been pivotal in identifying these mutations, facilitating more targeted management approaches. Conclusions: This case and review of literature underscore the importance of an integrated genetic, endocrine, and developmental approach in managing growth hormone deficiency (GHD) and IGF-1 resistance. The variability in growth disorders and response to therapy highlights the need for personalized treatment plans, informed by genetic insights, to optimize outcomes for patients with these complex conditions.