scholarly journals Central Precocious Puberty Caused by a Heterozygous Deletion in the MKRN3 Promoter Region

2018 ◽  
Vol 107 (2) ◽  
pp. 127-132 ◽  
Author(s):  
Delanie B. Macedo ◽  
Monica M. França ◽  
Luciana R. Montenegro ◽  
Marina Cunha-Silva ◽  
Danielle S. Bessa ◽  
...  

Context: Loss-of-function mutations in the coding region of MKRN3, a maternally imprinted gene at chromosome 15q11.2, are a common cause of familial central precocious puberty (CPP). Whether MKRN3 alterations in regulatory regions can cause CPP has not been explored to date. We aimed to investigate potential pathogenic variants in the promoter region of MKRN3 in patients with idiopathic CPP. Patients/Methods: A cohort of 110 patients with idiopathic CPP was studied. Family history of precocious sexual development was present in 25%. Mutations in the coding region of MKRN3 were excluded in all patients. Genomic DNA was extracted from peripheral blood leukocytes, and 1,100 nucleotides (nt) of the 5′-regulatory region of MKRN3 were amplified and sequenced. Luciferase assays were performed in GT1–7 cells transiently transfected with plasmids containing mutated and wild-type MKRN3 promoter. Results: We identified a rare heterozygous 4-nt deletion (c.-150_-147delTCAG; –38 to –41 nt upstream to the transcription start site) in the proximal promoter region of MKRN3 in a girl with CPP. In silico analysis predicted that this deletion would lead to the loss of a binding site for a downstream res­ponsive element antagonist modulator (DREAM), a potential transcription factor for MKRN3 and GNRH1 expression. Luciferase assays demonstrated a significant reduction of MKRN3 promoter activity in transfected cells with a c.-150_- 147delTCAG construct plasmid in both homozygous and heterozygous states when compared with cells transfected with the corresponding wild-type MKRN3 promoter region. Conclusion: A rare genetic alteration in the regulatory region of MKRN3 causes CPP.

2014 ◽  
Vol 99 (4) ◽  
pp. E647-E651 ◽  
Author(s):  
Nikolaos Settas ◽  
Catherine Dacou-Voutetakis ◽  
Maria Karantza ◽  
Christina Kanaka-Gantenbein ◽  
George P. Chrousos ◽  
...  

Context: Central precocious puberty (CPP), defined as the development of secondary sex characteristics prior to age 8 years in girls and 9 years in boys, results from the premature activation of the hypothalamic-pituitary-gonadal axis. Mutations in the imprinted gene MKRN3 have been recently implicated in familial cases of CPP. Objective: The objective of the study was to uncover the genetic cause of CPP in a family with two affected siblings. Design and participants: The entire coding region of the paternally expressed MKRN3 gene was sequenced in two siblings, a girl with CPP and her brother with early puberty, their parents, and their grandparents. Results: A novel heterozygous missense variant in the MKRN3 gene (p.C340G) was detected in the two affected siblings, their unaffected father, and the paternal grandmother. As expected, the mutated allele followed an imprinted mode of inheritance within the affected family. In silico analysis predicts the mutation as possibly damaging in all five software packages used. Furthermore, structural alignment of the ab initio native and mutant MKRN3 models predicts that the p.C340G mutation leads to significant structural perturbations in the 3-dimensional structure of the C3HC4 really interesting new gene motif of the protein, further emphasizing the functional implications of the novel MKRN3 alteration. Conclusions: We report a novel MKRN3 mutation (p.C340G) in a girl with CPP and her brother with early puberty. MKRN3 alterations should be suspected in all cases with familial CPP or early puberty, especially if male patients are also involved or the precocious puberty trend does not follow the usually observed mother-to-daughter inheritance.


2014 ◽  
Vol 99 (6) ◽  
pp. E1097-E1103 ◽  
Author(s):  
Delanie B. Macedo ◽  
Ana Paula Abreu ◽  
Ana Claudia S. Reis ◽  
Luciana R. Montenegro ◽  
Andrew Dauber ◽  
...  

Context: Loss-of-function mutations in makorin ring finger 3 (MKRN3), an imprinted gene located on the long arm of chromosome 15, have been recognized recently as a cause of familial central precocious puberty (CPP) in humans. MKRN3 has a potential inhibitory effect on GnRH secretion. Objectives: The objective of the study was to investigate potential MKRN3 sequence variations as well as copy number and methylation abnormalities of the 15q11 locus in patients with apparently sporadic CPP. Setting and Participants: We studied 215 unrelated children (207 girls and eight boys) from three university medical centers with a diagnosis of CPP. All but two of these patients (213 cases) reported no family history of premature sexual development. First-degree relatives of patients with identified MKRN3 variants were included for genetic analysis. Main Outcome Measures: All 215 CPP patients were screened for MKRN3 mutations by automatic sequencing. Multiplex ligation-dependent probe amplification was performed in a partially overlapping cohort of 52 patients. Results: We identified five novel heterozygous mutations in MKRN3 in eight unrelated girls with CPP. Four were frame shift mutations predicted to encode truncated proteins and one was a missense mutation, which was suggested to be deleterious by in silico analysis. All patients with MKRN3 mutations had classical features of CPP with a median age of onset at 6 years. Copy number and methylation abnormalities at the 15q11 locus were not detected in the patients tested for these abnormalities. Segregation analysis was possible in five of the eight girls with MKRN3 mutations; in all cases, the mutation was inherited on the paternal allele. Conclusions: We have identified novel inherited MKRN3 defects in children with apparently sporadic CPP, supporting a fundamental role of this peptide in the suppression of the reproductive axis.


2020 ◽  
Vol 4 (7) ◽  
Author(s):  
Stephanie A Roberts ◽  
Ana Paula Abreu ◽  
Victor M Navarro ◽  
Joy N Liang ◽  
Caroline A Maguire ◽  
...  

Abstract A critical body weight is necessary for pubertal development, an effect mediated in part by leptin. The potential regulation by leptin of Makorin Ring Finger Protein 3 (MKRN3), in which loss-of-function mutations are the most common genetic cause of central precocious puberty, has not been previously explored. In mice, expression of Mkrn3 in the hypothalamic arcuate nucleus is high early in life and declines before the onset of puberty. Therefore, we aimed to explore if leptin contributes to the decrease in hypothalamic Mkrn3 mRNA levels observed in mice during pubertal development. We first used a leptin-deficient (ob/ob) mouse model. Mkrn3 mRNA levels in the mediobasal hypothalamus (MBH), which includes the arcuate nucleus, and in the preoptic area (POA), both showed a significant decrease with age from postnatal day (PND) 12 to PND30 in ob/ob mice in both males and females, similar to that observed in wild-type mice. To further explore the effects of leptin on Mkrn3 expression, we exposed prepubertal wild-type mice to high levels of leptin from age PND9-12, which did not result in any significant difference in Mkrn3 expression levels in either the MBH or POA. In summary, regulation of Mkrn3 expression by leptin was not observed in either the MBH or the POA, 2 hypothalamic sites important for pubertal maturation. These data suggest that the decline in Mkrn3 at the onset of puberty may occur independently of leptin and support our hypothesis that MKRN3 is a bona fide controller of puberty initiation.


2015 ◽  
Vol 84 (1) ◽  
pp. 80-84 ◽  
Author(s):  
Vassos Neocleous ◽  
Christos Shammas ◽  
Marie M. Phelan ◽  
Stella Nicolaou ◽  
Leonidas A. Phylactou ◽  
...  

2011 ◽  
Vol 149 (4) ◽  
pp. 529-538 ◽  
Author(s):  
N. L. FEELEY ◽  
S. BOTTOMLEY ◽  
K. A. MUNYARD

SUMMARYThe coding region of the alpaca Agouti signalling protein (ASIP) gene was sequenced. It was determined to be 402 nucleotides long and code for a protein that is 133 amino acids long. Eight mutations were identified in a sample of 15 alpaca, five in the coding region and three in the introns flanking the exons. In silico analysis showed that three of the five mutations in the coding sequence, c.325_381del57, c.292C>T and c.353G>A are probable loss-of-function mutations. The three mutations were strongly associated with black fibre colour, with 0·90 of black alpacas in the current study having two copies of one or another of the mutations. However, not all black animals displayed the putative ‘aa’ genotype, and almost half of the non-black animals did display that genotype. Contributing factors such as regulatory region mutations, interactions of ASIP with melanocortin-1 receptor (MC1R) and α-melanocyte stimulating hormone (α-MSH), the effect of dilution genes and subjective phenotype assignment are discussed. These mutations will allow alpaca breeders to select for or against black, but they do not explain all black phenotypes in this species.


2005 ◽  
Vol 72 (3) ◽  
pp. 379-384 ◽  
Author(s):  
Maria Ballester ◽  
Armand Sánchez ◽  
Josep M Folch

β-lactoglobulin polymorphisms have been reported in the milk of different goat breeds, although no genetic variants affecting the protein have been characterized. In the present study, we amplified and sequenced the proximal promoter and the first six exons containing the entire coding region for the β-lactoglobulin gene in eleven goat breeds from Spain, France, Italy, Switzerland, Senegal and Asia to identify genetic variants. Fifteen polymorphisms were detected, nine in the promoter region and six in the exons of the β-lactoglobulin gene. All polymorphisms were single nucleotide substitutions with the exception of one deletion/insertion in the promoter region. The polymorphisms in the coding region did not produce any amino acid change. In addition, pyrosequencing technology was used to genotype four polymorphisms in the promoter region in 200 goats belonging to eleven breeds. Differences in allelic frequencies for these polymorphisms between breeds are described and a specific polymorphism for the Italian populations was identified. Finally, the analysis of association between these four promoter point mutations was investigated resulting in five haplotypes, GCGC being the most frequent haplotype in all breeds analysed.


Author(s):  
Carlos Eduardo Seraphim ◽  
Ana Pinheiro Machado Canton ◽  
Luciana Montenegro ◽  
Maiara Ribeiro Piovesan ◽  
Delanie B Macedo ◽  
...  

Abstract Context Loss-of-function mutations of makorin RING finger protein 3 (MKRN3) are the most common monogenic cause of familial central precocious puberty (CPP). Objective To describe the clinical and hormonal features of a large cohort of patients with CPP due to MKRN3 mutations and compare the characteristics of different types of genetic defects. Patients/methods Multiethnic cohort of 716 patients with familial or idiopathic CPP screened for MKRN3 mutations using Sanger sequencing. A group of 156 Brazilian girls with idiopathic CPP (ICPP) was used as control group. Results Seventy-one patients (45 girls and 26 boys from 36 families) had 18 different loss-of-function MKRN3 mutations. Eight mutations were classified as severe (70% of patients). Among the 71 patients, first pubertal signs occurred at 6.2 ± 1.2 years in girls and 7.1 ± 1.5 years in boys. Girls with MKRN3 mutations had a shorter delay between puberty onset and first evaluation and higher FSH levels compared to ICPP. Patients with severe MKRN3 mutations had a greater bone age advancement compared to patients with missense mutations (2·3 ± 1·6 vs. 1·6 ± 1·4 years, p = 0.048), and had higher basal LH levels (2·2 ± 1·8 vs. 1·1 ± 1·1 UI/L, p=0.018) at the time of presentation. Computational protein modeling revealed that 60% of the missense mutations were predicted to cause protein destabilization. Conclusions Inherited premature activation of the reproductive axis caused by loss-of-function mutations of MKRN3 is clinically indistinct from ICPP. However, the type of genetic defect may affect bone age maturation and gonadotropin levels.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xueling Yin ◽  
Junqi Wang ◽  
Tianting Han ◽  
Zhang Tingting ◽  
Yuhong Li ◽  
...  

Background: Central precocious puberty (CPP) is one of the most common and complex problems in clinical pediatric endocrinology practice. Mutation of the MKRN3 gene can cause familial CPP.Methods and Results: Here we reported a Chinese patient bearing a novel MKRN3 mutation (c.G277A/p.Gly93Ser) and showing the CPP phenotype. Functional studies found that this mutation of MKRN3 attenuated its autoubiquitination, degradation, and inhibition on the transcriptional activity of GNRH1, KISS1, and TAC3 promoters.Conclusion: MKRN3 (Gly93Ser) is a loss-of-function mutation, which attenuates the inhibition on GnRH1-related signaling, suggesting that this mutant can lead to central precocious puberty.


2020 ◽  
Vol 33 (8) ◽  
pp. 1045-1049
Author(s):  
Hae Sang Lee ◽  
Kyung Hee Kim ◽  
Jin Soon Hwang

AbstractObjectiveMutations in the delta-like 1 homolog (DLK1) gene have recently been reported in patients with idiopathic central precocious puberty (CPP). We aimed to investigate DLK1 mutations or polymorphisms in girls with CPP.MethodsA total of 100 girls diagnosed with idiopathic CPP were enrolled. DLK1 coding regions were sequenced in girls with idiopathic CPP and healthy girls (controls). The relationship between identified sequence variations and CPP was evaluated via comparison of allele frequencies between patients with CPP and normal healthy controls.ResultsWe identified five polymorphisms in DLK1. There was no significant difference with regard to allele frequency between patients with CPP and controls. Polymorphism c.549C>T (p.G183G) in DLK1 gene was identified in only one patient with CPP. In silico analysis with human splicing finder suggested that the variant (c.549C>T) leads to splicing defect.ConclusionsThe sequencing of DLK1 gene has uncovered only one potentially meaningful variant. However, our results demonstrate that DLK1 mutations are a relatively rare cause of idiopathic CPP.


Sign in / Sign up

Export Citation Format

Share Document