A Multicentric Brazilian Investigative Study of Copy Number Variations in Patients with Congenital Anomalies and Intellectual Disability.

Genomic imbalances are the most common cause of congenital anomalies (CA) and intellectual disability (ID). The aims of this study were to identify copy number variations (CNVs) in 416 patients with CA and ID from 5 different genetics centers within 4 different states by using the Multiplex Ligation-dependent Probe Amplification (MLPA) technique and to apply the chromosomal microarray (CMA) methodology in selected cases. The samples were analyzed by MLPA kits P064, P036, P070 and P250. Positive results were found in 97/416 (23.3%) patients. CMA was applied in 14 selected cases. In 6/14 (42.85%) patients, CMA detected other copy number variations not detected by the MLPA studies. Although CMA is indispensable for genotype refinement, the technique is still unfeasible in some countries as a routine analysis due to economic and technical limitations. In these cases, clinical evaluation followed by karyotyping and MLPA analysis is a helpful and affordable solution for diagnostic purposes.

Mucolipidosis II and III alpha/beta in Brazil: analysis of the GNPTAB gene.

UNLABELLED: Mucolipidosis II and III (MLII and MLIII) alpha/beta are rare autosomal recessive lysosomal storage diseases (LSDs) caused by pathogenic variations in the GNPTAB gene. GNPTAB gene codes for the α and ß subunits of phosphotransferase, the enzyme responsible for synthesis of the mannose-6-phosphate (M6P) marker that directs lysosomal enzymes to the lysosome. OBJECTIVES: The objective of this study is to identify sequence variations of the GNPTAB gene in Brazilian patients with MLII and MLIII alpha/beta. METHOD: Sequencing of the GNPTAB gene was performed in samples of gDNA extracted from the peripheral blood of patients with MLII/III diagnosed at a national reference center for LSDs. RESULTS: Twelve unrelated patients, from several regions of Brazil, were included in this study. Only one was born of consanguineous parents. All patients were found to carry at least one nonpathogenic variation. Nine causal sequence variations were found: c.242G>T (p.W81L); c.1123C>T (p.R375X); c.1196C>T (p.S399F); c.1208T>C (p.I403T); c.1514G>A (p.C505Y); c.1759C>T (p.R587X); c.2808A>G (p.Y937_M972del, novel mutation); c. 2269_2273delGAAAC (p.E757KfsX2, novel mutation); and c.3503_3504delTC (p.L1168QfsX5). Both pathogenic variations were identified in 8 of 12 patients; in four patients, only one pathogenic variation was identified. Mutation c.3503_3504delTC, located in exon 19, was the most frequent pathogenic variation found (n=11/24 alleles). The deleterious effect of the c.2808A>C mutation on splicing was confirmed by cDNA analysis. DISCUSSION/CONCLUSIONS: Our findings confirm that the GNPTAB gene presents broad allelic heterogeneity and suggests that, in Brazilian ML II and III patients, screening for mutations should begin at exon 19 of the GNPTAB gene. Further analyses will be conducted on patients in whom both pathogenic mutations have not been found in this study.

PTPN22 polymorphism is related to autoimmune disease risk in patients with Turner syndrome.

Individuals with Turner syndrome (TS) clearly have an increased risk for autoimmune diseases. Recently, an allelic variation (C1858T) of the PTPN22 gene was revealed to be associated with the development of autoimmunity. Thus, the aim of this study was to determine the frequency of the PTPN22 C1858T polymorphism in women with Turner syndrome (TS) compared to controls. Case-control study comprises 142 women with TS (cases) and 180 healthy and fertile women without a history of autoimmune disease (controls). Detection of the PTPN22 C1858T polymorphism (rs2476601) was performed by TaqMan real-time PCR. The chi-square test was used to compare allele and genotype frequencies between groups and to estimate the Hardy-Weinberg equilibrium. All P-values were two-tailed, and 95% confidence intervals (CIs) were calculated. A P-value <0.05 was considered statistically significant. Genotypes CC, CT and TT of the PTPN22 C1858T polymorphism presented frequencies of, respectively, 67.6%, 28.2% and 4.2% in the TS, and 82.8%, 16.1% and 1.1% in the control group (P = 0.0043). Alleles C and T were present in, respectively, 81.7% and 18.3% of the patients with TS (P = 0.001, OR = 2.22, 95% CI = 1.39-3.54) and in 90.8% and 9.2%, respectively, of the controls. The data suggest that in Brazilian patients with TS, the PTPN22 C1858T polymorphism may be an important genetic factor predisposing to autoimmune disease risk.

Blomstrand chondrodysplasia: a lethal sclerosing skeletal dysplasia. Case report and review.

We report a female stillborn with typical clinical, radiological, and anatomopathological features of Blomstrand chondrodysplasia. The main findings in this lethal osteochondrodysplasia are osteosclerosis and advanced skeletal maturation. Autosomal recessive inheritance has been proposed because of parental consanguinity of affected siblings in all reported cases, including this one. Histopathological study of the bones confirmed the advanced skeletal maturation radiological features. We also review this rare lethal osteochondrodysplasia.

Y-chromosome identification by PCR and gonadal histopathology in Turner's syndrome without overt Y-mosaicism.

OBJECTIVE: The frequency of gonadoblastoma is high in patients with Turner's syndrome bearing cells with Y or partial Y-chromosome. About 60% of patients with Turner's syndrome have a 45,X karyotype. In 30% of them a Y-sequence is disclosed by DNA analysis. To identify patients at risk of developing gonadoblastoma, a PCR based assay with SRY, ZFY and DYZ3 specific primers was carried out to detect different Y-sequences in the DNA of peripheral lymphocytes from patients with Turner's syndrome. DESIGN AND PATIENTS: Peripheral blood karyotypes from 36 patients with Turner's syndrome were studied. Patients with proven Y-chromosomal material were excluded. Genomic DNA was extracted from peripheral blood. SRY and ZFY genes and DYZ3 repetion of Y-chromosome were amplified by PCR. Patients with clinical signs of hyperandrogenism or with positive Y-sequences by PCR underwent gonadectomy. The gonadal tissues were examined for Y-sequences using PCR, morphology and immunohistochemical study. MEASUREMENTS: Turner's syndrome and signs of hyperandrogenism were evaluated both clinically and through laboratory tests. Haematoxylin and eosin staining was employed in gonadal morphology studies. The presence of testosterone was detected by immunohistochemistry using a monoclonal antibody. RESULTS: Two patients who had Y-positive blood samples and three hyperandrogenic (2 hirsutes, 1 virilized) Y-negatives underwent gonadectomy. PCR was carried out on their gonadal tissue. The tissue from the two patients without hyperandrogenism was Y-positive. The gonadal tissue from the three hyperandrogenics was Y-negative. Gonadal morphology disclosed hilus cell hyperplasia in the 3 hyperandrogenic Y-negatives and in one Y-positive patient; stromal luteoma and hyperthecosis in the virilized patient, cystadenofibroma in one hirsute patient and gonadoblastoma in one Y-positive. Testosterone was detected immunohistochemically in the hilus cell hyperplasia, stromal luteoma and hyperthecosis found in the hyperandrogenic patients. CONCLUSIONS: The molecular study was sensitive and useful in the evaluation of patients at risk of developing gonadoblastoma. Other nontumour, gonadotrophin-dependent and Y-independent mechanisms which deserve the same medical approach may be involved in the genesis of hyperandrogenic signs in Turner's syndrome.

Polidactilia pós-axial e miopia progressiva / Postaxial polydactyly and progressive myopia

O presente trabalho apresenta três casos de associaçäo de miopia progressiva com polidactilia pós-axial, sendo que dois säo irmäos do sexo masculino, filhos de casal näo consanguíneo e o terceiro caso é de uma menina filha de pais consanguíneos. Verificou-se na literatura apenas um relato, de Czeizel e Brooser, em 1986, em que é descrita a mesma associaçäo de defeitos, transmitindo-se em quatro geraçöes de forma autossômica dominante. Acreditamos que nossos pacientes apresentam a mesma síndrome, porém nestas duas famílias existem indícios de que a transmissäo ocorra de forma autossômica recessiva.