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"Jorge, Alexander A"
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Exome Sequencing Reveals the POLR3H Gene as a Novel Cause of Primary Ovarian Insufficiency
2019
Abstract
Context
Primary ovarian insufficiency (POI) is a cause of female infertility. However, the genetic etiology of this disorder remains unknown in most patients with POI.
Objective
To investigate the genetic etiology of idiopathic POI.
Patients and Methods
We performed whole-exome sequencing of 11 families with idiopathic POI. To gain insights into the potential mechanisms associated with this mutation, we generated two mouse lines via clustered regularly interspaced short palindromic repeats/Cas9 technology.
Results
A pathogenic homozygous missense mutation (c.149A>G; p.Asp50Gly) in the POLR3H gene in two unrelated families was identified. Pathogenic mutations in this subunit have not been associated with human disorders. Loss-of-function Polr3h mutation in mice caused early embryonic lethality. Mice with homozygous point mutation (Polr3hD50G) were viable but showed delayed pubertal development, characterized by late first estrus or preputial separation. The Polr3hD50G female and male mice showed decreased fertility later in life, associated with small litter size and increased time to pregnancy or to impregnate a female. Polr3hD50G mice displayed decreased expression of ovarian Foxo3a and lower numbers of primary follicles.
Conclusion
Our manuscript provides a case of POI caused by missense mutation in POLR3H, expanding the knowledge of molecular pathways of the ovarian function and human infertility. Screening of the POLR3H gene may elucidate POI cases without previously identified genetic causes, supporting approaches of genetic counseling.
This study revealed the first POLR3H mutation in two unrelated families with POI. The animal model showed delayed pubertal development and decreased fertility.
Journal Article
Precision Medicine for Cancer and Health Equity in Latin America: Generating Understanding for Policy and Health System Shaping
by
Alexander, Jorge A. Alatorre
,
Marinetti, Teresa
,
Barrios, Carlos
in
Cancer
,
Cancer therapies
,
Care and treatment
2025
This study presents and discusses evidence on the value of biomarker testing and precision medicine in Latin America through a health equity lens. It is essential to explore how to harness the benefits of precision medicine to narrow the health equity gap, ensuring all patients have access to the best cancer treatment. The methodology employed to develop this document consists of a non-systematic literature review, followed by a process of validation and feedback with a group of experts in relevant fields. Precision medicine could help reduce health inequities in Latin America by providing better diagnosis and treatment for everyone with cancer. However, its success in achieving this depends on the implementation of policies that promote equitable access. Findings indicate that the current policy landscape in the Latin American region is not conducive to improving access, reach, quality, or outcome-related problems in cancer care, nor to realizing the full potential of precision medicine. The study explores how precision medicine can advance health equity, concluding with an analysis of the challenges and recommendations for overcoming them.
Journal Article
Contributions of Common Genetic Variants to Constitutional Delay of Puberty and Idiopathic Hypogonadotropic Hypogonadism
by
Hall, Janet E
,
Seminara, Stephanie B
,
Palmert, Mark R
in
Adolescent
,
Adult
,
Case-Control Studies
2025
Abstract
Context
Constitutional delay of puberty (CDP) is highly heritable, but the genetic basis for CDP is largely unknown. Idiopathic hypogonadotropic hypogonadism (IHH) can be caused by rare genetic variants, but in about half of cases, no rare-variant cause is found.
Objective
To determine whether common genetic variants that influence pubertal timing contribute to CDP and IHH.
Design
Case-control study.
Participants
80 individuals with CDP; 301 with normosmic IHH, and 348 with Kallmann syndrome (KS); control genotyping data from unrelated studies.
Main Outcome Measures
Polygenic scores (PGS) based on genome-wide association studies for timing of male pubertal hallmarks and age at menarche (AAM).
Results
The CDP cohort had higher PGS for male pubertal hallmarks and for AAM compared to controls (for male hallmarks, Cohen's d = 0.67, P = 1 × 10−10; for AAM, d = 0.85, P = 1 × 10−16). The normosmic IHH cohort also had higher PGS for male hallmarks compared to controls, but the difference was smaller (male hallmarks d = 0.20, P = .003; AAM d = 0.10, P = .055). No differences were seen for the KS cohort compared to controls (male hallmarks d = 0.05, P = .45; AAM d = 0.03, P = .56).
Conclusion
Common genetic variants that influence pubertal timing in the general population contribute strongly to the genetics of CDP, weakly to normosmic IHH, and potentially not at all to KS. These findings demonstrate that the common-variant genetics of CDP and normosmic IHH are largely but not entirely distinct.
Journal Article
Genetics, clinical features and outcomes of non-syndromic pituitary gigantism: experience of a single center from Sao Paulo, Brazil
by
Mendonca, Berenice B
,
Jorge Alexander A L
,
Trarbach Ericka B
in
Diagnosis
,
DNA sequencing
,
Genetic screening
2021
PurposeNon-syndromic pituitary gigantism (PG) is a very rare disease. Aryl hydrocarbon receptor-interacting protein (AIP) and G protein-coupled receptor 101 (GPR101) genetic abnormalities represent important etiologic causes of PG and may account for up to 40% of these cases. Here, we aimed to characterize the clinical and molecular findings and long-term outcomes in 18 patients (15 males, three females) with PG followed at a single tertiary center in Sao Paulo, Brazil.MethodsGenetic testing for AIP and GPR101 were performed by DNA sequencing, droplet digital PCR and array comparative genomic hybridization (aCGH).ResultsPathogenic variants in the AIP gene were detected in 25% of patients, including a novel variant in splicing regulatory sequences which was present in a sporadic male case. X-LAG due to GPR101 microduplication was diagnosed in two female patients (12.5%). Of interest, these patients had symptoms onset by age 5 and 9 years old and diagnosis at 5 and 15 years, respectively. X-LAG, but not AIP, patients had a significantly lower age of symptoms onset and diagnosis and a higher height Z-score when compared to non-X-LAG. No other differences in clinical features and/or treatment outcomes were observed among PG based on their genetic background.ConclusionWe characterize the clinical and molecular findings and long-term outcome of the largest single-center PG cohort described so far.
Journal Article
Frequent development of combined pituitary hormone deficiency in patients initially diagnosed as isolated growth hormone deficiency: a long term follow-up of patients from a single center
by
Otto, Aline P.
,
Mendonca, Berenice B.
,
Carvalho, Luciani R. S.
in
Adolescent
,
Adrenocorticotropic Hormone - deficiency
,
Adult
2015
Background
Children initially diagnosed with isolated GH deficiency (IGHD) have a variable rate to progress to combined pituitary hormone deficiency (CPHD) during follow-up.
Objective
To evaluate the development of CPHD in a group of childhood-onset IGHD followed at a single tertiary center over a long period of time.
Patients and methods
We retrospectively analyzed data from 83 patients initially diagnosed as IGHD with a mean follow-up of 15.2 years. The Kaplan–Meier method and Cox regression analysis was used to estimate the temporal progression and to identify risk factors to development of CPHD over time.
Results
From 83 patients initially with IGHD, 37 (45 %) developed CPHD after a median time of follow up of 5.4 years (range from 1.2 to 21 years). LH and FSH deficiencies were the most common pituitary hormone (38 %) deficiencies developed followed by TSH (31 %), ACTH (12 %) and ADH deficiency (5 %). ADH deficiency (3.1 ± 1 years from GHD diagnosis) presented earlier and ACTH deficiency (9.3 ± 3.5 years) presented later during follow up compared to LH/FSH (8.3 ± 4 years) and TSH (7.5 ± 5.6 years) deficiencies. In a Cox regression model, pituitary stalk abnormalities was the strongest risk factor for the development of CPHD (hazard ratio of 3.28;
p
= 0.002).
Conclusion
Our study indicated a high frequency of development of CPHD in patients initially diagnosed as IGHD at childhood. Half of our patients with IGHD developed the second hormone deficiency after 5 years of diagnosis, reinforcing the need for lifelong monitoring of pituitary function in these patients.
Journal Article
Rare variants in SOS2 and LZTR1 are associated with Noonan syndrome
by
Gos, Monika
,
Naslavsky, Michel Satya
,
Bertola, Débora Romeo
in
Algorithms
,
Cohort Studies
,
Facies
2015
Background Noonan syndrome is an autosomal dominant, multisystemic disorder caused by dysregulation of the RAS/mitogen activated protein kinase (MAPK) pathway. Heterozygous, pathogenic variants in 11 known genes account for approximately 80% of cases. The identification of novel genes associated with Noonan syndrome has become increasingly challenging, since they might be responsible for very small fractions of the cases. Methods A cohort of 50 Brazilian probands negative for pathogenic variants in the known genes associated with Noonan syndrome was tested through whole-exome sequencing along with the relatives in the familial cases. Families from the USA and Poland with mutations in the newly identified genes were included subsequently. Results We identified rare, segregating or de novo missense variants in SOS2 and LZTR1 in 4% and 8%, respectively, of the 50 Brazilian probands. SOS2 and LZTR1 variants were also found to segregate in one American and one Polish family. Notably, SOS2 variants were identified in patients with marked ectodermal involvement, similar to patients with SOS1 mutations. Conclusions We identified two novel genes, SOS2 and LZTR1, associated with Noonan syndrome, thereby expanding the molecular spectrum of RASopathies. Mutations in these genes are responsible for approximately 3% of all patients with Noonan syndrome. While SOS2 is a natural candidate, because of its homology with SOS1, the functional role of LZTR1 in the RAS/MAPK pathway is not known, and it could not have been identified without the large pedigrees. Additional functional studies are needed to elucidate the role of LZTR1 in RAS/MAPK signalling and in the pathogenesis of Noonan syndrome.
Journal Article
DLK1 Is a Novel Link Between Reproduction and Metabolism
by
Baracat, Edmund C
,
Mendonca, Berenice B
,
Montenegro, Luciana R
in
Adipogenesis
,
Adolescent
,
Adult
2019
Delta-like homolog 1 (DLK1), also called preadipocyte factor 1, prevents adipocyte differentiation and has been considered a molecular gatekeeper of adipogenesis. A DLK1 complex genomic defect was identified in five women from a single family with central precocious puberty (CPP) and increased body fat percentage.
We studied 60 female patients with a diagnosis of CPP or history of precocious menarche. Thirty-one of them reported a family history of precocious puberty. DLK1 DNA sequencing was performed in all patients. Serum DLK1 concentrations were measured using an ELISA assay in selected cases. Metabolic and reproductive profiles of adult women with CPP caused by DLK1 defects were compared with those of 20 women with idiopathic CPP.
We identified three frameshift mutations of DLK1 (p.Gly199Alafs*11, p.Val271Cysfs*14, and p.Pro160Leufs*50) in five women from three families with CPP. Segregation analysis was consistent with the maternal imprinting of DLK1. Serum DLK1 concentrations were undetectable in three affected women. Metabolic abnormalities, such as overweight/obesity, early-onset glucose intolerance/type 2 diabetes mellitus, and hyperlipidemia, were more prevalent in women with the DLK1 mutation than in the idiopathic CPP group. Notably, the human metabolic alterations were similar to the previously described dlk1-null mice phenotype. Two sisters who carried the p.Gly199Alafs*11 mutation also exhibited polycystic ovary syndrome and infertility.
Loss-of-function mutations of DLK1 are a definitive cause of familial CPP. The high prevalence of metabolic alterations in adult women who experienced CPP due to DLK1 defects suggests that this antiadipogenic factor represents a link between reproduction and metabolism.
Journal Article
Influence of growth hormone receptor (GHR) exon 3 and -202A/C IGFBP-3 genetic polymorphisms on clinical and biochemical features and therapeutic outcome of patients with acromegaly
by
Bronstein, Marcello D.
,
Duarte, Felipe H.
,
Trarbach, Ericka B.
in
Acromegaly - blood
,
Acromegaly - diagnosis
,
Acromegaly - genetics
2015
Background
The association of GHR-exon 3 and -202 A/C IGFBP3 polymorphisms with clinical presentation, biochemical measurements and response to therapies in acromegaly have been suggested.
Objective
To evaluate the presence of these polymorphisms in acromegaly and their influence on clinical and laboratorial characteristics of patients at diagnosis and after treatment in a large cohort of acromegalic patients.
Patients and methods
This is a cross-sectional study developed in a single tertiary reference center. Clinical data were obtained from the medical records of 186 acromegalic patients (116 women, age range 21–88 years). GH and IGF1 levels and GHR-exon 3 and -202 A/C IGFBP3 polymorphisms were evaluated in the same hospital.
Results
At diagnosis, serum GH concentrations were lower in patients with GHR-d3 genotype than those with GHR-fl, whereas an association of lower IGFBP3 levels with d3 allele was observed only after neurosurgical or medical treatments. However, these associations were not confirmed in posterior statistical analysis.
Conclusion
Our results suggest that GHR-exon 3 and -202 A/C IGFBP3 polymorphisms did not show any consistent association on clinical and laboratorial features of acromegalic patients even after treatment.
Journal Article
Multigene Sequencing Analysis of Children Born Small for Gestational Age With Isolated Short Stature
by
Malaquias, Alexsandra C
,
Lerario, Antônio M
,
Arnhold, Ivo J P
in
Body Height - genetics
,
Body Weight - genetics
,
Bone dysplasia
2019
Abstract
Context
Patients born small for gestational age (SGA) who present with persistent short stature could have an underlying genetic etiology that will account for prenatal and postnatal growth impairment. We applied a unique massive parallel sequencing approach in cohort of patients with exclusively nonsyndromic SGA to simultaneously interrogate for clinically substantial genetic variants.
Objective
To perform a genetic investigation of children with isolated short stature born SGA.
Design
Screening by exome (n = 16) or targeted gene panel (n = 39) sequencing.
Setting
Tertiary referral center for growth disorders.
Patients and Methods
We selected 55 patients born SGA with persistent short stature without an identified cause of short stature.
Main Outcome Measures
Frequency of pathogenic findings.
Results
We identified heterozygous pathogenic or likely pathogenic genetic variants in 8 of 55 patients, all in genes already associated with growth disorders. Four of the genes are associated with growth plate development, IHH (n = 2), NPR2 (n = 2), SHOX (n = 1), and ACAN (n = 1), and two are involved in the RAS/MAPK pathway, PTPN11 (n = 1) and NF1 (n = 1). None of these patients had clinical findings that allowed for a clinical diagnosis. Seven patients were SGA only for length and one was SGA for both length and weight.
Conclusion
These genomic approaches identified pathogenic or likely pathogenic genetic variants in 8 of 55 patients (15%). Six of the eight patients carried variants in genes associated with growth plate development, indicating that mild forms of skeletal dysplasia could be a cause of growth disorders in this group of patients.
In the present study, molecular investigation, using massive parallel sequencing, showed effectiveness in diagnosing one in seven patients with prenatal short stature of unknown etiology.
Journal Article