Growth hormone insensitivity: Mexican case report

Homozygous 6-bp deletion of IGFALS in a prepubertal boy with short stature

Biallelic IGFALS variants lead to acid‒labile subunit (ALS) deficiency characterized by growth hormone resistance with or without delayed puberty. Here, we report a prepubertal boy with a homozygous 2-amino acid deletion within the fourth N-glycosylation motif (c.1103_1108del, p.N368_S370delinsT) associated with parental consanguinity. He showed short stature consistent with ALS deficiency. This case expands the mutation spectrum of IGFALS to include the elimination of only one N-glycosylation motif of ALS.

Role of the GH-IGF1 axis on the hypothalamus-pituitary-testicular axis function: lessons from Laron syndrome

BACKGROUND

Animal studies suggest that insulin-like growth factor 1 (IGF1) may influence the function of the hypothalamus-pituitary-testicular axis, especially in childhood, but the evidence in humans is scanty. Laron syndrome, a human model of IGF1 deficiency, may help to solve this issue.

PURPOSE

This systematic review aims to analyze puberty onset and progression, testicular volume, gonadotropin, and total testosterone serum levels, sperm parameters and fertility, and penile length in patients with Laron syndrome.

METHODS

Specific keywords were used. All data on male patients with Laron syndrome were included.

RESULTS

Seventeen articles matched the inclusion criteria and were entered in the analysis, for a total of 125 male patients. Puberty was absent in 8.9% and delayed in 35.6% of untreated patients of pubertal age. After onset, the duration of the pubertal process was prolonged in 76.9% of untreated patients. The growth spurt was absent in 52.6% and delayed in 31.6% of untreated patients. The testicular volume was small in the two patients who did not receive any treatment. Treatment with IGF1 increased gonadotropin and testosterone serum levels in five out of five patients of pubertal age. No effect was found in four out of four patients younger than 5 years. No study reported data on sperm parameters and fertility. Micropenis occurred in 67.2% of patients.

CONCLUSION AND FUTURE PERSPECTIVES

Delayed puberty is common in patients with Laron syndrome. The growth hormone-IGF1 axis may influence the time of puberty onset. Serum levels of IGF1 should be investigated in children with delayed puberty, scarce progression of testicular growth, and/or micropenis. IGF1 levels might be measured in children with delayed puberty, poor testicular growth, and/or micropenis.

Is insulin-like growth factor-1 involved in Parkinson's disease development?

Parkinson's disease (PD) is a neurodegenerative disorder that results in the death of dopaminergic neurons within the substantia nigra pars compacta and the reduction in dopaminergic control over striatal output neurons, leading to a movement disorder most commonly characterized by akinesia or bradykinesia, rigidity and tremor. Also, PD is less frequently depicted by sensory symptoms (pain and tingling), hyposmia, sleep alterations, depression and anxiety, and abnormal executive and working memory related functions. On the other hand, insulin-like growth factor 1 (IGF-1) is an endocrine, paracrine and autocrine hormone with several functions including tissue growth and development, insulin-like activity, proliferation, pro-survival, anti-aging, antioxidant and neuroprotection, among others. Herein this review tries to summarize all experimental and clinical data to understand the pathophysiology and development of PD, as well as its clear association with IGF-1, supported by several lines of evidence: (1) IGF-1 decreases with age, while aging is the major risk for PD establishment and development; (2) numerous basic and translational data have appointed direct protective and homeostasis IGF-1 roles in all brain cells; (3) estrogens seem to confer women strong protection to PD via IGF-1; and (4) clinical correlations in PD cohorts have confirmed elevated IGF-1 levels at the onset of the disease, suggesting an ongoing compensatory or "fight-to-injury" mechanism.

Diagnosis of Laron syndrome using monoplex-polymerase chain reaction technology with a whole-genome amplification template: A case report

BACKGROUND

Laron syndrome (LS) is an autosomal recessive hereditary condition affecting only 1/1000000 births. The cause is associated with mutations in the growth hormone (GH) receptor (GHR), leading to GH insensitivity. LS patients typically present with severe growth retardation, obesity, and abnormal sexual maturation. Currently, LS diagnosis is performed post-delivery. Therefore, we assessed the efficiency of Pre-implantation Genetic Testing (PGT) coupled with monoplex-polymerase chain reaction (PCR) technology for detecting this monogenic disease in embryos from a couple confirmed as LS heterozygous carriers.

CASE SUMMARY

The couple LS-carriers were confirmed by the presence of a first child born with LS. The couple underwent a standard in vitro fertilization (IVF) protocol. DNA was collected from trophectoderm cells from day 5 embryos. Whole genome amplification (WGA) was performed using a Sureplex DNA Amplification System and analyzed by PCR, targeting the deletion of the exons 5 and 6 in the GHR gene as well as PGT by Next-generation Sequencing (Illumina). Eleven embryos were collected and analyzed. 27.3% were the wild type for GHR, 45.5% were heterozygotes, and 18.2% homozygous mutants. One embryo yielded no results. Three 2-embryos transfers were performed; 2 normal homozygous and four heterozygous carriers were selected for transfer. The first two transfers were unsuccessful, whereas the final transfer with two heterozygous embryos resulted in clinical pregnancy. The genomic composition of the fetus was verified, applying the same techniques using amniocytes, extracted after 21 wk of the ongoing pregnancy. The fetus was confirmed as GHR deletion in exon 5-6, carrier. A non-affected baby was born.

CONCLUSION

Here, we present a case demonstrating that using WGA as a template in addition to PCR targeting specific gene regions, exons 5 and 6 on the GHR gene, could identify LS carrier embryos. This provides evidence that WGA and PCR serve as an excellent tool to detect this specific monogenic disease in IVF embryos, thus allowing selection of candidate embryos for transfer successfully when a specific inherited genetic mutation/disease is suspected.