RESUMEN
Turner syndrome (TS) is characterized by the presence of one full X chromosome and total or partial deletion of the second sex chromosome. Diagnosis of TS is often delayed, resulting in inappropriate treatment. Early diagnosis of TS using a neonatal screening test may improve preventive measures and treatment, thus improving patient quality of life. The goal of this study was to standardize a neonatal TS screening algorithm. Two study genes (ARSE and MAGEH1) and 1 normalizing gene (HBB) were used to detect the second X chromosome. We screened 996 newborns whose peripheral blood was collected and stored in filter paper. In addition, samples from 20 patients with confirmed diagnosis of TS were included in the study. Relative amounts of ARSE/HBB were determined using real-time polymerase chain reaction. The cutoff at the 5th percentile was arbitrarily set to indicate repetition of the test. The test was repeated in 51/1016 patients with ARSE/HBB < 0.81. For 10 samples with values persistently <0.81, we quantified the MAGEH1/HBB ratio. Values below the 95th percentile in TS patients (MAGEH1/HBB < 1.24) were considered to be inadequate. Only 6/996 NB showed inadequate values for the 2 studied genes, which were recalled for clinical evaluation and karyotype testing. Analysis of 20 patients diagnosed with TS allowed for identification of false-negatives and true-positives, establishing 95% sensitivity when the indicated cutoff values were used. In conclusion, our algorithm reached 95% detection sensitivity with an acceptable recall rate (0.6%), allowing for the detection of suspected TS cases in the neonatal period.
Asunto(s)
Arilsulfatasas/genética , Pruebas Genéticas/métodos , Proteínas Asociadas a Microtúbulos/genética , Proteínas de Neoplasias/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Síndrome de Turner/genética , Algoritmos , Femenino , Humanos , Recién Nacido , Cariotipo , Cariotipificación , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Análisis de Secuencia de ADN , Síndrome de Turner/diagnóstico , Globinas beta/genéticaRESUMEN
Androgen action is exerted through the androgen receptor. The normal 46,XY genital virilization depends on androgen receptor gene expression, which is tissue specific, and requires normal androgen receptor mRNA levels in androgen sensitive tissues. Hypospadias is a frequent male genital abnormality, potentially related to reduced androgen sensitivity in genital tissues. The aim of this study was to compare, by quantitative real time PCR, the amount of androgen receptor mRNA in cells obtained from the urethral mucosa of patients with middle idiopathic hypospadias with the androgen receptor mRNA levels observed in control phimosis subjects with eutopic urethral opening. Prepubertal individuals were studied, including 41 controls and 17 hypospadias patients with mean (SD) ages of 4.7 (2.1) years and 4.0 (3.0) years, respectively. We observed significantly less androgen receptor mRNA in the urethral mucosa of patients with hypospadias than in the controls (p=0.002). The correlation between the level of androgen receptor mRNA expression and the penile size was almost statistically significant only in hypospadias patients (r=0.47; p=0.053). We also established the number of CAG repeats in exon 1 of the androgen receptor gene by GeneScan analysis. No significant difference was observed in the number of CAG repeats when patients and controls were compared. A negative correlation between the CAG repeats and penile size was detected in patients with hypospadias, but not in controls. Our data suggest that a critical lower level of androgen receptor mRNA expression could be a determining factor in the development of middle hypospadias.
Asunto(s)
Regulación hacia Abajo , Hipospadias/genética , Membrana Mucosa/metabolismo , Receptores Androgénicos/genética , Uretra/metabolismo , Estudios de Casos y Controles , Niño , Preescolar , Exones , Humanos , Hipospadias/metabolismo , Hipospadias/patología , Lactante , Masculino , Membrana Mucosa/crecimiento & desarrollo , Tamaño de los Órganos , Pene/crecimiento & desarrollo , Pene/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores Androgénicos/metabolismo , Repeticiones de Trinucleótidos , Uretra/crecimiento & desarrolloRESUMEN
Normal testosterone levels are frequently observed in women with androgenetic alopecia (AGA), suggesting the involvement of androgen sensitivity in this condition. Androgen sensitivity is related to androgen receptor (AR) messenger RNA (mRNA) production in hair follicles and is negatively related to the number of CAG repeats present in exon 1 of the AR gene. The aim of this study was to compare AR expression in AGA women with normal controls and to correlate this expression with the number of CAG repeats. Hair follicles were obtained from 27 women with AGA and 21 controls for AR gene expression analysis. AR expression was evaluated through AR mRNA quantification using real-time polymerase chain reaction and the number of CAG repeats in the AR gene was determined in complementary DNA samples obtained from hair follicles and analyzed with the Gene Scan software. AR mRNA in the frontal-parietal region was significantly higher than in the occipital region of AGA patients (paired t-test, P = 0.046). No significant difference was identified in controls (P = 0.67). Both regions in the same individual showed a significant positive correlation in AGA patients (r = 0.77; P < 0.05) and in controls (r = 0.91; P < 0.05). A negative correlation was identified between AR expression and the number of CAG repeats only in AGA patients (r = 0.510; P = 0.013). The identification of elevated AR mRNA quantitation in hair follicles is a useful tool for identifying potentially abnormal androgen sensitivity in AGA patients.
Asunto(s)
Alopecia/genética , Folículo Piloso/metabolismo , Receptores Androgénicos/genética , Adulto , Anciano , Alelos , ADN Complementario/genética , Exones/genética , Femenino , Regulación de la Expresión Génica , Técnicas de Genotipaje , Humanos , Persona de Mediana Edad , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores Androgénicos/metabolismo , Expansión de Repetición de Trinucleótido/genética , Adulto JovenRESUMEN
Insulin resistance is an underlying cause of metabolic changes associated with cardiovascular diseases. Glucocorticoids are known determinant factors of insulin resistance. We quantified glucocorticoid receptor alpha (GRα) mRNA and 11 beta-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) mRNA in various tissues of 35 patients with previously established cardiovascular disease. This was a prospective study in a cardiac surgery patient setting. Samples of subcutaneous adipose tissue, epicardial fat, muscle, and peripheral blood mononuclear cells were examined. GRα and 11ß-HSD1 mRNA were determined by real-time PCR. Mean age was 54.4 years. A significantly higher level of GRα mRNA was observed in muscle, with mean = 43.6 arbitrary units, median (p25-p75) = 39.4, compared to epicardial adipose tissue, with mean = 34.2, median (p25-p75) = 27.6, and to subcutaneous adipose tissue, with mean = 29.0, median (p25-p75) = 19.0, and lymphocytes, with mean = 17.5, median (p25-p75) = 14.02. When patients with diabetes mellitus were compared to patients without insulin resistance, significantly lower levels of GRα mRNA were observed in epicardial fat. Lymphocytes had the lowest 11ß-HSD1 mRNA concentration. We also observed significantly reduced 11ß-HSD1 mRNA levels in visceral fat when compared with muscle tissue. GRα and 11ß-HSD1 mRNA levels differed among tissues involved in the pathophysiology of metabolic syndrome. We conclude that epicardial adipose tissue has lower GRαmRNA levels in insulin-resistant patients; this seems to be an adaptive and protective mechanism.
Asunto(s)
Adaptación Fisiológica/genética , Resistencia a la Insulina/genética , Especificidad de Órganos/genética , Receptores de Glucocorticoides/genética , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/genética , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/metabolismo , Adulto , Anciano , Enfermedades Cardiovasculares/genética , Enfermedades Cardiovasculares/fisiopatología , Enfermedades Cardiovasculares/cirugía , Femenino , Regulación de la Expresión Génica , Humanos , Grasa Intraabdominal/metabolismo , Grasa Intraabdominal/patología , Grasa Intraabdominal/fisiopatología , Masculino , Persona de Mediana Edad , Pericardio/metabolismo , Pericardio/patología , Pericardio/fisiopatología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores de Glucocorticoides/metabolismoRESUMEN
Turner syndrome (TS) is the complete or partial loss of the second sex chromosome, occurring in 1:5 000 girls. Early recognition allows appropriate therapy for short stature and puberty. Neonatal diagnosis of TS permits detection of associated malformations, minimizing sequels. Aiming to develop a molecular method for the diagnosis of TS we employed blood samples stored on filter paper. We evaluated 78 female controls, 25 TS girls with 45,X karyotype, and 32 TS patients with other karyotypes. After DNA extraction, samples were submitted to real-time PCR, using primers and probes directed to the study gene ARSE and to the control gene GAPDH. A ROC curve established the ARSE:GAPDH ratio with a cutoff value of 0.7. Low ARSE:GAPDH ratio of <0.7 was present in 100% of 45,X TS patients. This cutoff value presented a sensitivity of 100% and a specificity of 100% in detecting 45,X TS patients with a positive predictive value of 100% and a negative predictive value of 100%. The same cutoff value was able to identify only 56% of TS with other karyotypes, in which we observed a mean (SD) ARSE:GAPDH ratio=0.66 (0.2); and the interquartile range=0.4-0.8. Determination of ARSE:GAPDH ratio is a fast, sensitive, and specific method, with viable cost and feasible automation, which makes it potentially applicable in neonatal screening programs for the diagnosis of Turner syndrome 45,X.
Asunto(s)
Tamizaje Neonatal/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Síndrome de Turner/diagnóstico , Síndrome de Turner/genética , Arilsulfatasas/genética , Estudios de Casos y Controles , Dosificación de Gen/genética , Humanos , Recién Nacido , CariotipificaciónRESUMEN
Turner syndrome (TS) is one of the most common chromosomal abnormalities among girls. Complete monosomy of X chromosome is responsible for almost 50% of all cases of TS, and mosaicism and X anomaly are detected in the other half. It has already been demonstrated that early diagnosis of these children allows appropriate growth hormone treatment with better final height prognosis and introduction of estrogen at an ideal chronological age. Sixty-four short-stature girls were selected and the clinical data obtained were birth weight and height, weight and height at the first medical visit and target height. Other clinical data including cardiac and renal abnormalities, otitis, Hashimoto thyroiditis, cubitus valgus, short neck, widely separated nipples, and pigmented nevi were obtained from the patients' medical records. The aim of the present study was to evaluate the screening of a group of short-stature girls for TS based on the number of CAG repeats of the androgen receptor gene analyzed by GeneScan software. Patient samples with two alleles (heterozygous) were 49/64 (76.5%) and with one allele (homozygous) were 15/64 (23.5%). A karyotype was determined in 30 patients, 9 homozygous and 21 heterozygous. In the homozygous group, 6/9 were 45,X and 3/9 were 46,XX. In the heterozygous group, 17/21 were 46,XX, and 4/21 were TS patients with mosaicism (45,X/46,XX; 45,X/46XiXq; 46XdelXp). The pattern obtained by GeneScan in two patients with mosaicism in the karyotype was an imbalance between the peak heights of the two alleles, suggesting that this imbalance could be present when there is a mosaicism. The frequency of TS abnormalities (18.7%) did not differ between TS and 46,XX girls. Thus, it is important to accurately assess the incidence of TS in growth-retarded girls, even in the absence of other dysmorphisms. In this study, we diagnosed 6 cases of TS 45,X (9.4%) by molecular analysis, with a 100% sensitivity and 85% specificity. This molecular analysis was able to detect all cases of TS 45,X and the majority of mosaicisms, without the need for more X chromosome markers. In conclusion, determining the number of CAG repeats of the androgen receptor gene analyzed by GeneScan was a fast method with high sensitivity for the detection of TS 45,X, suggesting that it could be interesting as a method for screening a population of growth-retarded girls.
Asunto(s)
Estatura/genética , Exones , Receptores Androgénicos/genética , Repeticiones de Trinucleótidos/genética , Síndrome de Turner/diagnóstico , Alelos , Niño , Femenino , Marcadores Genéticos , Heterocigoto , Homocigoto , Humanos , Cariotipificación , Mosaicismo , Sensibilidad y Especificidad , Estadística como Asunto , Factores de TiempoRESUMEN
Turner syndrome (TS) is one of the most common chromosomal abnormalities among girls. Complete monosomy of X chromosome is responsible for almost 50% of all cases of TS, and mosaicism and X anomaly are detected in the other half. It has already been demonstrated that early diagnosis of these children allows appropriate growth hormone treatment with better final height prognosis and introduction of estrogen at an ideal chronological age. Sixty-four short-stature girls were selected and the clinical data obtained were birth weight and height, weight and height at the first medical visit and target height. Other clinical data including cardiac and renal abnormalities, otitis, Hashimoto thyroiditis, cubitus valgus, short neck, widely separated nipples, and pigmented nevi were obtained from the patients medical records. The aim of the present study was to evaluate the screening of a group of short-stature girls for TS based on the number of CAG repeats of the androgen receptor gene analyzed by GeneScan software. Patient samples with two alleles (heterozygous) were 49/64 (76.5%) and with one allele (homozygous) were 15/64 (23.5%). A karyotype was determined in 30 patients, 9 homozygous and 21 heterozygous. In the homozygous group, 6/9 were 45,X and 3/9 were 46,XX. In the heterozygous group, 17/21 were 46,XX, and 4/21 were TS patients with mosaicism (45,X/46,XX; 45,X/46XiXq; 46XdelXp). The pattern obtained by GeneScan in two patients with mosaicism in the karyotype was an imbalance between the peak heights of the two alleles, suggesting that this imbalance could be present when there is a mosaicism. The frequency of TS abnormalities (18.7%) did not differ between TS and 46,XX girls. Thus, it is important to accurately assess the incidence of TS in growth-retarded girls, even in the absence of other dysmorphisms. In this study, we diagnosed 6 cases of TS 45,X (9.4%) by molecular analysis, with a 100% sensitivity and 85% specificity. This molecular analysis was...