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1.
J Genet Couns ; 32(1): 250-259, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36204975

RESUMEN

Sex chromosome aneuploidies (SCAs), including 47,XXY, 47,XXX, 47,XYY, and supernumerary variants, occur collectively in approximately one of 500 live births. Clinical phenotypes are highly variable resulting in previous ascertainment rates estimated to be only 10%-25% during a lifetime. Historically, prenatal SCA diagnoses were incidental findings, accounting for ≤10% of cases, with the majority of diagnoses occurring postnatally during evaluations for neurodevelopmental, medical, or infertility concerns. The initiation of noninvasive prenatal screening (NIPS) in 2012 and adoption into standardized obstetric care provides a unique opportunity to significantly increase prenatal ascertainment of SCAs. However, the impact NIPS has had on ascertainment of SCAs is understudied, particularly for those who may defer diagnostic testing until after birth. This study evaluates the timing of diagnostic testing following positive NIPS in 152 infants with SCAs and potential factors influencing this decision. Eighty-seven (57%) elected to defer diagnostic testing after a positive NIPS until birth, and 8% (7/87) of those confirmed after birth were found to have discordant results on postnatal diagnostic testing, most of which would have influenced genetic counseling.


Asunto(s)
Pruebas Prenatales no Invasivas , Embarazo , Femenino , Humanos , Aneuploidia , Diagnóstico Prenatal/métodos , Aberraciones Cromosómicas Sexuales , Consejo
2.
Am J Med Genet C Semin Med Genet ; 184(2): 327-333, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32542985

RESUMEN

Klinefelter syndrome (KS) occurs in 1:600 males and is associated with high morbidity and mortality due to diabetes and cardiovascular disease. Up to 50% of men with KS have metabolic syndrome, a cluster of features conferring increased risk for diabetes and cardiovascular disease. These cardiometabolic (CM) risk features have not been studied in adolescents with KS. The objective of this cohort study was to compare CM risk features in adolescents with KS to controls matched for sex, age, and BMI z score. Fifty males with KS (age 10-17 years) were well-matched to male controls (n = 50) for age (14.0 ± 1.7 vs. 14.0 ± 1.5 years) and BMI z score (0.3 ± 1.3 vs. 0.4 ± 1.2). Three CM risk features were present in 30% of adolescents with KS compared to 12% of controls (RR 2.5, 95% CI 1.1-5.9, p = .048). The KS group had significantly lower HDL cholesterol (p = .006), higher triglycerides (p < .001), and greater waist circumference percentile (p < .001). Despite a normal BMI, the prevalence of CM risk features was very high in adolescents with KS, particularly for central adiposity and dyslipidemia. The pathophysiology of this metabolic profile independent of obesity needs further investigation to facilitate prevention of the high morbidity of cardiovascular disease and diabetes in this population. ClinicalTrials.gov identifiers: NCT01585831 and NCT02723305.


Asunto(s)
Enfermedades Cardiovasculares/epidemiología , Diabetes Mellitus/epidemiología , Síndrome de Klinefelter/epidemiología , Obesidad/epidemiología , Adolescente , Índice de Masa Corporal , Factores de Riesgo Cardiometabólico , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/patología , Estudios de Casos y Controles , Niño , Estudios de Cohortes , Diabetes Mellitus/sangre , Diabetes Mellitus/patología , Femenino , Humanos , Síndrome de Klinefelter/sangre , Síndrome de Klinefelter/patología , Masculino , Síndrome Metabólico/sangre , Síndrome Metabólico/epidemiología , Síndrome Metabólico/patología , Obesidad/sangre , Obesidad/patología , Testosterona/sangre , Triglicéridos/sangre , Circunferencia de la Cintura
3.
Genet Med ; 22(10): 1682-1693, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32475986

RESUMEN

PURPOSE: Deep phenotyping is an emerging trend in precision medicine for genetic disease. The shape of the face is affected in 30-40% of known genetic syndromes. Here, we determine whether syndromes can be diagnosed from 3D images of human faces. METHODS: We analyzed variation in three-dimensional (3D) facial images of 7057 subjects: 3327 with 396 different syndromes, 727 of their relatives, and 3003 unrelated, unaffected subjects. We developed and tested machine learning and parametric approaches to automated syndrome diagnosis using 3D facial images. RESULTS: Unrelated, unaffected subjects were correctly classified with 96% accuracy. Considering both syndromic and unrelated, unaffected subjects together, balanced accuracy was 73% and mean sensitivity 49%. Excluding unrelated, unaffected subjects substantially improved both balanced accuracy (78.1%) and sensitivity (56.9%) of syndrome diagnosis. The best predictors of classification accuracy were phenotypic severity and facial distinctiveness of syndromes. Surprisingly, unaffected relatives of syndromic subjects were frequently classified as syndromic, often to the syndrome of their affected relative. CONCLUSION: Deep phenotyping by quantitative 3D facial imaging has considerable potential to facilitate syndrome diagnosis. Furthermore, 3D facial imaging of "unaffected" relatives may identify unrecognized cases or may reveal novel examples of semidominant inheritance.


Asunto(s)
Cara , Imagenología Tridimensional , Cara/diagnóstico por imagen , Humanos , Síndrome
4.
Int J Neonatal Screen ; 10(3)2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-39051404

RESUMEN

Sex chromosome aneuploidies (SCAs) collectively occur in 1 in 500 livebirths, and diagnoses in the neonatal period are increasing with advancements in prenatal and early genetic testing. Inevitably, SCA will be identified on either routine prenatal or newborn screening in the near future. Tetrasomy SCAs are rare, manifesting more significant phenotypes compared to trisomies. Prenatal cell-free DNA (cfDNA) screening has been demonstrated to have relatively poor positive predictive values (PPV) in SCAs, directing genetic counseling discussions towards false-positive likelihood rather than thoroughly addressing all possible outcomes and phenotypes, respectively. The eXtraordinarY Babies study is a natural history study of children prenatally identified with SCAs, and it developed a longitudinal data resource and common data elements with the Newborn Screening Translational Research Network (NBSTRN). A review of cfDNA and diagnostic reports from participants identified a higher than anticipated rate of discordance. The aims of this project are to (1) compare our findings to outcomes from a regional clinical cytogenetic laboratory and (2) describe discordant outcomes from both samples. Twenty-one (10%), and seven (8.3%) cases were found to be discordant between cfDNA (result or indication reported to lab) and diagnosis for the Babies Study and regional laboratory, respectively. Discordant results represented six distinct discordance categories when comparing cfDNA to diagnostic results, with the largest groups being Trisomy cfDNA vs. Tetrasomy diagnosis (66.7% of discordance in eXtraordinarY Babies study) and Mosaicism (57.1% in regional laboratory). Traditional genetic counseling for SCA-related cfDNA results is inadequate given a high degree of discordance that jeopardizes the accuracy of the information discussed and informed decision making following prenatal genetic counseling.

5.
medRxiv ; 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39211864

RESUMEN

Introduction: Autism spectrum disorder (ASD) is a neurodevelopmental disorder commonly associated with behavioral challenges. There are few evidence based pharmacological interventions available for the treatment of behavioral symptoms associated with ASD. Cannabidiol (CBD), the non-psychoactive component of cannabis, has potential neuroprotective, antiepileptic, anxiolytic, and antipsychotic effects and may be useful in treating the behavioral symptoms of ASD. Methods: We describe the research methods of a 27-week double-blind placebo-controlled cross-over trial of cannabidiol for the treatment of irritability and aggression associated with ASD, utilizing the irritability subscale of the Aberrant Behavior Checklist-2nd edition (ABC-2) as the primary outcome measure. Adverse effects and safety monitoring protocols are included. Several secondary and exploratory outcomes measures also include anxiety, communication, repetitive behaviors, attention, hyperactivity, autism family experience, and telehealth functional behavior assessment. Conclusion: There is a significant need for clinical research exploring alternative medications for the treatment of behavioral symptoms of ASD. Cannabidiol (CBD) is being studied for the management of irritability, aggression, and other problem behaviors associated with ASD.

6.
Cell Genom ; 4(1): 100462, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38190107

RESUMEN

Somatic cells of human males and females have 45 chromosomes in common, including the "active" X chromosome. In males the 46th chromosome is a Y; in females it is an "inactive" X (Xi). Through linear modeling of autosomal gene expression in cells from individuals with zero to three Xi and zero to four Y chromosomes, we found that Xi and Y impact autosomal expression broadly and with remarkably similar effects. Studying sex chromosome structural anomalies, promoters of Xi- and Y-responsive genes, and CRISPR inhibition, we traced part of this shared effect to homologous transcription factors-ZFX and ZFY-encoded by Chr X and Y. This demonstrates sex-shared mechanisms by which Xi and Y modulate autosomal expression. Combined with earlier analyses of sex-linked gene expression, our studies show that 21% of all genes expressed in lymphoblastoid cells or fibroblasts change expression significantly in response to Xi or Y chromosomes.


Asunto(s)
Factores de Transcripción , Cromosoma Y , Humanos , Masculino , Femenino , Factores de Transcripción/genética , Cromosomas Humanos X/genética , Aberraciones Cromosómicas Sexuales , Expresión Génica/genética
7.
Cell Genom ; 3(2): 100259, 2023 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-36819663

RESUMEN

The "inactive" X chromosome (Xi) has been assumed to have little impact, in trans, on the "active" X (Xa). To test this, we quantified Xi and Xa gene expression in individuals with one Xa and zero to three Xis. Our linear modeling revealed modular Xi and Xa transcriptomes and significant Xi-driven expression changes for 38% (162/423) of expressed X chromosome genes. By integrating allele-specific analyses, we found that modulation of Xa transcript levels by Xi contributes to many of these Xi-driven changes (≥121 genes). By incorporating metrics of evolutionary constraint, we identified 10 X chromosome genes most likely to drive sex differences in common disease and sex chromosome aneuploidy syndromes. We conclude that human X chromosomes are regulated both in cis, through Xi-wide transcriptional attenuation, and in trans, through positive or negative modulation of individual Xa genes by Xi. The sum of these cis and trans effects differs widely among genes.

8.
bioRxiv ; 2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37333288

RESUMEN

Somatic cells of human males and females have 45 chromosomes in common, including the "active" X chromosome. In males the 46th chromosome is a Y; in females it is an "inactive" X (Xi). Through linear modeling of autosomal gene expression in cells from individuals with zero to three Xi and zero to four Y chromosomes, we found that Xi and Y impact autosomal expression broadly and with remarkably similar effects. Studying sex-chromosome structural anomalies, promoters of Xi- and Y-responsive genes, and CRISPR inhibition, we traced part of this shared effect to homologous transcription factors - ZFX and ZFY - encoded by Chr X and Y. This demonstrates sex-shared mechanisms by which Xi and Y modulate autosomal expression. Combined with earlier analyses of sex-linked gene expression, our studies show that 21% of all genes expressed in lymphoblastoid cells or fibroblasts change expression significantly in response to Xi or Y chromosomes.

9.
Mol Genet Genomic Med ; 9(12): e1833, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34738344

RESUMEN

BACKGROUND: Supernumerary sex chromosome aneuploidies (SCA) are common genetic conditions characterized by additional X or Y chromosome, affecting ~1/500 individuals, with the most frequent karyotypes of 47,XXY (Klinefelter syndrome), 47,XXX (Trisomy X), and 47,XYY (Jacob syndrome). Although there is considerable phenotypic variation among these diagnoses, these conditions are characterized by the presence of overlapping physical, medical, developmental, and psychological features. Our interdisciplinary clinic's experience anecdotally supports previous published findings of atopic conditions, feeding difficulties, and gastroesophageal reflux to be more prevalent in SCAs (Bardsley et al., Journal of Pediatrics, 2013, 163, 1085; Samango-Sprouse et al., The Application of Clinical Genetics, 2019, 12, 191; Tartaglia et al., Acta Paediatrica, 2008, 100, 851). Furthermore, we observed that many of these patients have also been diagnosed with eosinophilic esophagitis (EoE), an association not currently reported in the literature. METHODS: We conducted a retrospective chart review of all 667 patients with SCA seen at a large tertiary care center to investigate the prevalence and presenting features of EoE. RESULTS: Four percent of children with SCAs had a biopsy-confirmed diagnosis of EoE, which represents an odds ratio of 32 (95% CI 6-185) when compared to the prevalence rates reported in the general population. CONCLUSION: Routine screening for EoE symptoms may be warranted for individuals with SCA and atopic conditions.


Asunto(s)
Aneuploidia , Esofagitis Eosinofílica/diagnóstico , Esofagitis Eosinofílica/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Cromosomas Sexuales , Adolescente , Adulto , Niño , Preescolar , Diagnóstico Diferencial , Registros Electrónicos de Salud , Esofagitis Eosinofílica/epidemiología , Estudios de Asociación Genética/métodos , Pruebas Genéticas , Humanos , Lactante , Síndrome de Klinefelter/diagnóstico , Síndrome de Klinefelter/genética , Prevalencia , Estudios Retrospectivos , Adulto Joven
10.
Front Pharmacol ; 12: 757825, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34690787

RESUMEN

Background: Fragile X syndrome (FXS), the most common single-gene cause of intellectual disability and autism spectrum disorder (ASD), is caused by a >200-trinucleotide repeat expansion in the 5' untranslated region of the fragile X mental retardation 1 (FMR1) gene. Individuals with FXS can present with a range of neurobehavioral impairments including, but not limited to: cognitive, language, and adaptive deficits; ASD; anxiety; social withdrawal and avoidance; and aggression. Decreased expression of the γ-aminobutyric acid type A (GABAA) receptor δ subunit and deficient GABAergic tonic inhibition could be associated with symptoms of FXS. Gaboxadol (OV101) is a δ-subunit-selective, extrasynaptic GABAA receptor agonist that enhances GABAergic tonic inhibition, providing the rationale for assessment of OV101 as a potential targeted treatment of FXS. No drug is approved in the United States for the treatment of FXS. Methods: This 12-weeks, randomized (1:1:1), double-blind, parallel-group, phase 2a study was designed to assess the safety, tolerability, efficacy, and optimal daily dose of OV101 5 mg [once (QD), twice (BID), or three-times daily (TID)] when administered for 12 weeks to adolescent and adult men with FXS. Safety was the primary study objective, with key assessments including treatment-emergent adverse events (TEAEs), treatment-related adverse events leading to study discontinuation, and serious adverse events (SAEs). The secondary study objective was to evaluate the effect of OV101 on a variety of problem behaviors. Results: A total of 23 participants with FXS (13 adolescents, 10 adults) with moderate-to-severe neurobehavioral phenotypes (Full Scale Intelligence Quotient, 41.5 ± 3.29; ASD, 82.6%) were randomized to OV101 5 mg QD (n = 8), 5 mg BID (n = 8), or 5 mg TID (n = 7) for 12 weeks. OV101 was well tolerated across all 3 treatment regimens. The most common TEAEs were upper respiratory tract infection (n = 4), headache (n = 3), diarrhea (n = 2), and irritability (n = 2). No SAEs were reported. Improvements from baseline to end-of-treatment were observed on several efficacy endpoints, and 60% of participants were identified as treatment responders based on Clinical Global Impressions-Improvement. Conclusions: Overall, OV101 was safe and well tolerated. Efficacy results demonstrate an initial signal for OV101 in individuals with FXS. These results need to be confirmed in a larger, randomized, placebo-controlled study with optimal outcomes and in the most appropriate age group. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03697161.

11.
Reprod Sci ; 27(11): 1985-1991, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32578162

RESUMEN

An extra X chromosome occurs in ~ 1 in 1000 females, resulting in a karyotype 47,XXX also known as trisomy X syndrome (TXS). Women with TXS appear to be at increased risk for premature ovarian insufficiency; however, very little research on this relationship has been conducted. The objective of this case-control study is to compare ovarian function, as measured by anti-mullerian hormone (AMH) levels, between girls with TXS and controls. Serum AMH concentrations were compared between 15 females with TXS (median age 13.4 years) and 26 controls (median age 15.1 years). Females with TXS had significantly lower serum AMH compared to controls (0.7 ng/mL (IQR 0.2-1.7) vs 2.7 (IQR 1.3-4.8), p < 0.001). Additionally, girls with TXS were much more likely to have an AMH below the 2.5th percentile for age with 67% of them meeting these criteria (OR 11, 95% CI 2.3-42). Lower AMH concentrations in females with TXS may represent an increased risk for primary ovarian insufficiency in these patients and potentially a narrow window of opportunity to pursue fertility preservation options. Additional research is needed to understand the natural history of low AMH concentrations and future risk of premature ovarian insufficiency in girls with TXS.


Asunto(s)
Reserva Ovárica , Insuficiencia Ovárica Primaria/fisiopatología , Trastornos de los Cromosomas Sexuales del Desarrollo Sexual/complicaciones , Adolescente , Adulto , Hormona Antimülleriana/sangre , Estudios de Casos y Controles , Niño , Cromosomas Humanos X , Estradiol/sangre , Femenino , Gonadotropinas/sangre , Humanos , Insuficiencia Ovárica Primaria/sangre , Insuficiencia Ovárica Primaria/complicaciones , Aberraciones Cromosómicas Sexuales , Trastornos de los Cromosomas Sexuales del Desarrollo Sexual/sangre , Trisomía , Adulto Joven
12.
J Endocr Soc ; 3(12): 2276-2285, 2019 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-31737857

RESUMEN

CONTEXT: Boys with XXY have greater adiposity and a higher risk of cardiovascular disease. Infants with XXY have lower testosterone concentrations than typical boys, but no studies have evaluated adiposity in infants with XXY or the physiologic effects of giving testosterone replacement. OBJECTIVE: To determine the effect of testosterone on body composition in infants with XXY. DESIGN: Prospective, randomized trial. SETTING: Tertiary care pediatric referral center. PARTICIPANTS: 20 infants 6 to 15 weeks of age with 47,XXY. INTERVENTION: Testosterone cypionate 25 mg intramuscularly monthly for three doses vs no treatment. MAIN OUTCOME MEASURES: Difference in change in adiposity (percent fat mass z scores); other body composition measures, penile length, and safety outcomes between treated and untreated infants; and comparison with typical infants. RESULTS: The increase in percent fat mass (%FM) z scores was greater in the untreated group than in the treated group (+0.92 ± 0.62 vs -0.12 ± 0.65, P = 0.004). Increases in secondary outcomes were greater in the testosterone-treated group for total mass, fat-free mass, length z score, stretched penile length, and growth velocity (P < 0.002 for all). At 5 months of age, adiposity in untreated infants with XXY was 26.7% compared with 23.2% in healthy male infants of the same age (P = 0.0037); there was no difference in %FM between the treated XXY boys and controls. Reported side effects were minimal and self-limited; no serious adverse events occurred. CONCLUSIONS: Adiposity of untreated infants was 15% greater than that of male controls by 5 months of age. Testosterone treatment for infants with XXY resulted in positive changes in body composition.

13.
J Dev Behav Pediatr ; 38(3): 197-207, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28333849

RESUMEN

OBJECTIVE: Neurodevelopmental concerns in males with sex chromosome aneuploidy (SCA) (XXY/Klinefelter syndrome, XYY, XXYY) include symptoms seen in autism spectrum disorder (ASD), such as language impairments and social difficulties. We aimed to: (1) evaluate ASD characteristics in research cohorts of SCA males under DSM-IV compared to DSM-5 criteria, and (2) analyze factors associated with ASD diagnoses in SCA. METHODS: Evaluation of participants with XXY/KS (n=20), XYY (n=57) and XXYY (n=21) included medical history, cognitive/adaptive testing, Social Communication Questionnaire, Social Responsiveness Scale, Autism Diagnostic Observation Schedule, Autism Diagnostic Interview-Revised, and DSM ASD criteria. Clinical impressions of ASD diagnostic category using the ADOS and DSM-IV criteria were compared to ADOS-2 and DSM-5 criteria. T-tests compared cognitive, adaptive, SES and prenatal vs. postnatal diagnoses between ASD and no ASD groups. RESULTS: ASD rates in these research cohorts were 10% in XXY/KS, 38% in XYY, and 52% in XXYY using ADOS-2/DSM-5, and were not statistically different compared to DSM-IV criteria. In XYY and XXYY, the ASD group had lower verbal IQ and adaptive functioning compared to those without ASD. Many children without ASD still showed some social difficulties. CONCLUSION: ASD rates in males with SCA are higher than reported for the general population. Males with Y chromosome aneuploidy (XYY and XXYY) were 4.8 times more likely to have a diagnosis of ASD than the XXY/KS group, and 20 times more likely than males in the general population (1 in 42 males, CDC 2010). ASD should be considered when evaluating social difficulties in SCA. Studies of SCA and Y-chromosome genes may provide insight into male predominance in idiopathic ASD.


Asunto(s)
Trastorno del Espectro Autista/epidemiología , Trastorno del Espectro Autista/fisiopatología , Síndrome de Klinefelter/epidemiología , Cariotipo XYY/epidemiología , Adolescente , Adulto , Niño , Preescolar , Comorbilidad , Humanos , Masculino , Índice de Severidad de la Enfermedad , Adulto Joven
14.
J Dev Behav Pediatr ; 33(4): 309-18, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22333574

RESUMEN

OBJECTIVE: Attentional problems, hyperactivity, and impulsivity have been described as behavioral features associated with sex chromosome aneuploidy (SCA). In this study, the authors compare attention-deficit hyperactivity disorder (ADHD) symptoms in 167 participants aged 6 to 20 years with 4 types of SCA (XXY n = 56, XYY n = 33, XXX n = 25, and XXYY n = 53). They also evaluate factors associated with ADHD symptomatology (cognitive and adaptive scores, prenatal vs postnatal ascertainment) and describe the clinical response to psychopharmacologic medications in a subset of patients treated for ADHD. METHODS: Evaluation included medical and developmental history, cognitive and adaptive functioning assessment, and parent and teacher ADHD questionnaires containing DSM-IV criteria. RESULTS: In the total study group, 58% (96/167) met DSM-IV criteria for ADHD on parent-report questionnaires (36% in XXY, 52% in XXX, 76% in XYY, and 72% in XXYY). The Inattentive subtype was most common in XXY and XXX, whereas the XYY and XXYY groups were more likely to also have hyperactive/impulsive symptoms. There were no significant differences in Verbal, Performance, or Full Scale IQ between children with symptom scores in the ADHD range compared with those below the ADHD range. However, adaptive functioning scores were significantly lower in the group whose scores in the ADHD range were compared with those of the group who did not meet ADHD DSM-IV criteria. Those with a prenatal diagnosis of XXY were less likely to meet criteria for ADHD compared with the postnatally diagnosed group. Psychopharmacologic treatment with stimulants was effective in 78.6% (66/84). CONCLUSIONS: Children and adolescents with SCA are at increased risk for ADHD symptoms. Recommendations for ADHD evaluation and treatment in consideration of other aspects of the SCA medical and behavioral phenotype are provided.


Asunto(s)
Desarrollo del Adolescente/fisiología , Aneuploidia , Trastorno por Déficit de Atención con Hiperactividad/diagnóstico , Desarrollo Infantil/fisiología , Aberraciones Cromosómicas Sexuales , Adolescente , Adulto , Trastorno por Déficit de Atención con Hiperactividad/etiología , Niño , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Diagnóstico Prenatal , Escalas de Valoración Psiquiátrica , Tetrasomía/fisiopatología , Trisomía/fisiopatología , Escalas de Wechsler , Cariotipo XYY/fisiopatología , Adulto Joven
15.
Int J Pediatr Endocrinol ; 2012(1): 8, 2012 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-22524164

RESUMEN

BACKGROUND: Male sex chromosome aneuploidies are underdiagnosed despite concomitant physical and behavioral manifestations. OBJECTIVE: To develop a non-invasive, rapid and high-throughput molecular diagnostic assay for detection of male sex chromosome aneuploidies, including 47,XXY (Klinefelter), 47,XYY, 48,XXYY and 48,XXXY syndromes. METHODS: The assay utilizes three XYM and four XA markers to interrogate Y:X and X:autosome ratios, respectively. The seven markers were PCR amplified using genomic DNA isolated from a cohort of 323 males with aneuploid (n = 117) and 46,XY (n = 206) karyotypes. The resulting PCR products were subjected to Pyrosequencing, a quantitative DNA sequencing method. RESULTS: Receiver operator characteristic (ROC) curves were used to establish thresholds for the discrimination of aneuploid from normal samples. The XYM markers permitted the identification of 47,XXY, 48,XXXY and 47,XYY syndromes with 100% sensitivity and specificity in both purified DNA and buccal swab samples. The 48,XXYY karyotype was delineated by XA marker data from 46,XY; an X allele threshold of 43% also permitted detection of 48,XXYY with 100% sensitivity and specificity. Analysis of X chromosome-specific biallelic SNPs demonstrated that 43 of 45 individuals (96%) with 48,XXYY karyotype had two distinct X chromosomes, while 2 (4%) had a duplicate X, providing evidence that 48,XXYY may result from nondisjunction during early mitotic divisions of a 46,XY embryo. CONCLUSIONS: Quantitative Pyrosequencing, with high-throughput potential, can detect male sex chromosome aneuploidies with 100% sensitivity.

16.
Eur J Hum Genet ; 20(12): 1240-7, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22617343

RESUMEN

Copy number variants (CNVs) and intragenic rearrangements of the NRXN1 (neurexin 1) gene are associated with a wide spectrum of developmental and neuropsychiatric disorders, including intellectual disability, speech delay, autism spectrum disorders (ASDs), hypotonia and schizophrenia. We performed a detailed clinical and molecular characterization of 24 patients who underwent clinical microarray analysis and had intragenic deletions of NRXN1. Seventeen of these deletions involved exons of NRXN1, whereas seven deleted intronic sequences only. The patients with exonic deletions manifested developmental delay/intellectual disability (93%), infantile hypotonia (59%) and ASDs (56%). Congenital malformations and dysmorphic features appeared infrequently and inconsistently among this population of patients with NRXN1 deletions. The more C-terminal deletions, including those affecting the ß isoform of neurexin 1, manifested increased head size and a high frequency of seizure disorder (88%) when compared with N-terminal deletions of NRXN1.


Asunto(s)
Moléculas de Adhesión Celular Neuronal/genética , Exones/genética , Eliminación de Gen , Genotipo , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/genética , Proteínas del Tejido Nervioso/genética , Fenotipo , Anomalías Múltiples/diagnóstico , Anomalías Múltiples/genética , Adolescente , Adulto , Proteínas de Unión al Calcio , Niño , Trastornos Generalizados del Desarrollo Infantil/diagnóstico , Trastornos Generalizados del Desarrollo Infantil/genética , Variaciones en el Número de Copia de ADN , Femenino , Humanos , Lactante , Intrones , Masculino , Análisis por Micromatrices , Hipotonía Muscular/congénito , Hipotonía Muscular/diagnóstico , Hipotonía Muscular/genética , Moléculas de Adhesión de Célula Nerviosa , Isoformas de Proteínas/genética
17.
Orphanet J Rare Dis ; 5: 8, 2010 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-20459843

RESUMEN

Trisomy X is a sex chromosome anomaly with a variable phenotype caused by the presence of an extra X chromosome in females (47,XXX instead of 46,XX). It is the most common female chromosomal abnormality, occurring in approximately 1 in 1,000 female births. As some individuals are only mildly affected or asymptomatic, it is estimated that only 10% of individuals with trisomy X are actually diagnosed. The most common physical features include tall stature, epicanthal folds, hypotonia and clinodactyly. Seizures, renal and genitourinary abnormalities, and premature ovarian failure (POF) can also be associated findings. Children with trisomy X have higher rates of motor and speech delays, with an increased risk of cognitive deficits and learning disabilities in the school-age years. Psychological features including attention deficits, mood disorders (anxiety and depression), and other psychological disorders are also more common than in the general population. Trisomy X most commonly occurs as a result of nondisjunction during meiosis, although postzygotic nondisjunction occurs in approximately 20% of cases. The risk of trisomy X increases with advanced maternal age. The phenotype in trisomy X is hypothesized to result from overexpression of genes that escape X-inactivation, but genotype-phenotype relationships remain to be defined. Diagnosis during the prenatal period by amniocentesis or chorionic villi sampling is common. Indications for postnatal diagnoses most commonly include developmental delays or hypotonia, learning disabilities, emotional or behavioral difficulties, or POF. Differential diagnosis prior to definitive karyotype results includes fragile X, tetrasomy X, pentasomy X, and Turner syndrome mosaicism. Genetic counseling is recommended. Patients diagnosed in the prenatal period should be followed closely for developmental delays so that early intervention therapies can be implemented as needed. School-age children and adolescents benefit from a psychological evaluation with an emphasis on identifying and developing an intervention plan for problems in cognitive/academic skills, language, and/or social-emotional development. Adolescents and adult women presenting with late menarche, menstrual irregularities, or fertility problems should be evaluated for POF. Patients should be referred to support organizations to receive individual and family support. The prognosis is variable, depending on the severity of the manifestations and on the quality and timing of treatment.


Asunto(s)
Aberraciones Cromosómicas Sexuales , Trisomía/diagnóstico , Trisomía/patología , Femenino , Asesoramiento Genético , Humanos , Cariotipificación , Diagnóstico Prenatal/métodos , Trisomía/genética , Trisomía/fisiopatología
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