Inactivating PLEKHA6 Mutations Cause Idiopathic Hypogonadotropic Hypogonadism Through Impaired Kisspeptin Secretion
PLEKHA6 has been identified as a novel gene linked to idiopathic hypogonadotropic hypogonadism, with variants impairing kisspeptin secretion. Further research is needed to understand the clinical relevance of these findings.
Where it sits
this study against the rest of the kisspeptin (kp-10) corpusSummary and findings
This study investigated the genetic basis of idiopathic hypogonadotropic hypogonadism (IHH) by analyzing exome and genome sequencing data from 1,822 patients. The researchers identified 18 distinct PLEKHA6 variants in 24 patients, which were associated with impaired kisspeptin secretion. The findings suggest a novel role for PLEKHA6 in the regulation of kisspeptin secretion.
Abstract
<h4>ABSTRACT</h4> <h4>Purpose</h4> Idiopathic hypogonadotropic hypogonadism (IHH) is characterized by impaired reproductive maturation, and approximately half of all cases lack an identified genetic cause. We investigated the genetic basis of IHH in two large cohorts to identify novel disease-causing genes. <h4>Methods</h4> We analyzed exome and genome sequencing data from 1,822 patients with IHH from two independent cohorts. Rare variants were filtered using pedigree-informed inheritance models. PLEKHA6 expression in the postmortem human hypothalamus were tested at the mRNA and protein level. Functional studies assessed kisspeptin secretion in cell-based assays. <h4>Results</h4> We identified 18 distinct PLEKHA6 variants in 24 patients from 20 unrelated families (1.3% of cohort). Variants segregated with disease under autosomal recessive and autosomal dominant (with variable penetrance) inheritance patterns. PLEKHA6 was robustly expressed in the hypothalamus and showed clear colocalization with neurokinin B, which served as the marker for the GnRH pulse generator. Functional studies demonstrated that patient variants significantly impaired kisspeptin secretion. <h4>Conclusion</h4> PLEKHA6 is a novel IHH gene and the first reported regulator of kisspeptin secretion from the kisspeptin-neurokinin B-dynorphin (KNDy) neurons, which have recently been established as the GnRH pulse generator. These findings establish impaired kisspeptin release as a new disease mechanism in IHH and highlight the critical role of neuropeptide trafficking in reproductive function.
Background
This paper addresses the genetic underpinnings of idiopathic hypogonadotropic hypogonadism (IHH), a condition characterized by impaired reproductive maturation. Prior research has identified various genetic causes of IHH, but approximately half of the cases remain unexplained. Understanding the genetic basis of IHH is crucial for developing targeted interventions and enhancing reproductive health.
Methods
The study analyzed exome and genome sequencing data from 1,822 patients with IHH across two independent cohorts. Rare variants were filtered using pedigree-informed inheritance models. PLEKHA6 expression was assessed in postmortem human hypothalamus at both the mRNA and protein levels, while functional studies evaluated kisspeptin secretion in cell-based assays.
Results
The primary finding was the identification of 18 distinct PLEKHA6 variants in 24 patients, representing 1.3% of the cohort. These variants were found to segregate with the disease under both autosomal recessive and dominant inheritance patterns. PLEKHA6 expression was confirmed in the hypothalamus, and functional studies indicated that the patient variants significantly impaired kisspeptin secretion.
Interpretation
The findings of this study suggest that PLEKHA6 is a novel gene associated with IHH and plays a critical role in kisspeptin secretion. While the association is statistically significant, the clinical implications of these findings need to be further explored. Potential confounds include the reliance on genetic data from a specific population and the need for additional functional studies to confirm the role of PLEKHA6 in kisspeptin regulation.
Key findings
- 18 distinct PLEKHA6 variants identified in 24 patients from 20 unrelated families (1.3% of cohort).
- Variants segregated with disease under autosomal recessive and autosomal dominant inheritance patterns.
- PLEKHA6 was robustly expressed in the hypothalamus.
- Functional studies demonstrated that patient variants significantly impaired kisspeptin secretion.
Limitations
- 1.3% of cohort with identified variants may limit generalizability.
- Study relies on genetic data from specific populations.
- Functional implications of variants require further investigation.