Same Phenotype in Children with Growth Hormone Deficiency and Resistance

Are androstenedione, dihydrotestosterone, thyroid-stimulating hormone, insulin-like growth factor I, and insulin-like growth factor binding protein 3 necessary for isolated micropenis healthy boys' evaluation without any phenotypic abnormalities? A cross-sectional study

The study aimed to familiarise primary care physicians and specialists with the minimum hormonal diagnostic tests necessary to assay isolated micropenis in healthy children without any phenotypic abnormality. Children aged 6-15 years (mean 11.6 ± 1.68) were assessed from May 2010 to September 2021 (N = 247). Multiple regression analysis showed correlations between stretched penile length (SPL) and hormonal assays as follows: follicle-stimulating hormone (FSH): r = 0.097, p = 0.035; luteinizing hormone (LH): r = 0.139, p = 0.012, thyroid-stimulating hormone (TSH): r = -0.001, p = 0.321; testosterone (T): r = 0.118, p = 0.004; dihydrotestosterone (DHT): r = 0.002, p = 0.243; androstenedione (Δ4And): r = -0.004, p = 0.502; insulin-like growth factor I (IGF-I): r = -0.003, p = 0.062; and IFG-binding protein 3 (IGF-BP₃ ): r = 0.052, p = 0.051. The most hormonal disorder was testosterone deficiency. TSH, Δ4And, and DHT were normal in all boys. SPL was significantly correlated with FSH, LH, and T, but there was no significant correlation between SPL and TSH, DHT, Δ4And, IGF-I, and IGF-BP₃ . Whenever the isolated micropenis is seen without other anomalies, it is sufficient to assay testosterone, FSH, and LH in the first step.

Isolated growth hormone deficiency type IA due to a novel GH1 variant: a case report

BACKGROUND

A case of isolated growth hormone deficiency type IA (IGHD IA) caused by novel compound heterozygous mutation in the GH1 gene was reported in this study, which aimed to provide insights that will benefit future diagnosis and treatment.

CASE PRESENTATION

We analyzed and summarized the clinical data and genetic test results from a patient with IGHD admitted in March 2019 to the Department of Pediatrics Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology. We described the results from a 1-year-9-months old female, whose chief complaint was "growth retardation for more than one year". Her birth length was 49.0 cm, and her birth weight was 3.05 kg. Suboptimal intake (breastfeeding) jaundice lasted for approximately two months following birth. When evaluated at the age of 1-year-9-months old, the patient's height was 61.0 cm (- 7.24 SD), and her weight was 6.4 kg (- 1.50 SD). The patient's physical characteristics included yellowish hair, large and unclosed anterior fontanelles, raised forehead, and a low and flat nose. The major abnormalities observed from the auxiliary examinations included low GH (< 0.05 μg/l), low IGF-1 (16.99 μg/l), and elevated TSH (6.97 mIU/l). Genetic testing revealed two heterozygous variants: a splicing mutation (NG_011676.1(NM_022560.4): c.10 + 1G>T, inherited from her mother) in intron 1 of the GH1 gene and a deletion that encompassed the same gene (chr17: 61973811-61996255, inherited from her father). After hormone replacement therapy with L-thyroxine and recombinant human GH (rhGH), the patient's thyroid function returned to normal, and her serum IGF-1 level significantly improved, which resulted in an accelerated increase in height.

CONCLUSION

This study described a case of IGHD caused by novel compound heterozygous mutations in the GH1 gene. This study suggested that closer attention should be directed to genetic testing and diagnosis based on clinical characteristics to avoid misdiagnosis.

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.