Difficulties in the diagnosis of HbS/beta thalassemia: Really a mild disease?

Background: HbS/b cases having clinical, hematologic and electrophoretic similarities cannot be sufficiently distinguished from sickle cell anemia cases and are misdiagnosed as sickle cell anemia. This study will investigate the congruence between the HPLC thalassemia scanning tests and the laboratory findings compared to the DNA sequence analysis results of the patients diagnosed with SCA between 2016 and 2020. This study also aims to indicate the current status to accurately diagnose sickle cell anemia and HbS/b in the light of hematologic, electrophoretic and molecular studies. Methods: Fourteen patients who were diagnosed with SCA in hospitals at different cities in Turkey and followed by the Thalassemia Diagnosis, Treatment and Research Center, Mugla Sitki Koçman University were included in this retrospective study. The socio-demographic characteristics, hemogram, hemoglobin variant analysis results and DNA chain analysis results of the patients were taken from the database of the centre and then examined. The informed consents were taken from the patients. The patients were administered a survey containing questions about transfusion history and diagnostic awareness. The Beta-Thalassemia mutations were analysed using a DNA sequencer (Dade Behring, Germany) based on the Sanger method. Results: According to the DNA sequence analysis, the results of these patients diagnosed with SCA in hospitals in different cities of Turkey were the following: of 14 patients, 8 had HbS/b0, and HbS/b+ and one had HbS carrier, and one had Hb-O, and three had SCA. The patient with HbS carrier status also contains three additional mutations, all of which are heterozygous. We discovered that although two of three mutations, which are c.315+16G>C and c.316-185C>T, are previously reported as benign, at least one of the two mentioned mutations, when combined with HbS, causes transfusion-dependent HbS/b. Conclusions: Briefly, HbSS and HbS/b thalassemia genotypes cannot be definitely characterized by electrophoretic and hematologic data, resulting in misdiagnosis. c.315+16G>C and c.316-185C>T are previously reported as benign; at least one of the two mentioned mutations, when combined with HbS, causes transfusion-dependent HbS/b. In undeveloped or some developing countries, molecular diagnosis methods and genetic analyses cannot be used. If mutation analyses could be performed, then such differential diagnosis errors would reduce. However, if mutation analysis cannot be performed, other methods such as HPLC, capillary electrophoresis absolutely be sought to have insight into the parental carriage status.

Introducción del genotipaje molecular de los antigenos plaquetarios / Introduction of molecular genotypingof plateles antigens

Introducción: Los antígenos plaquetarios humanos (HPA) se expresan en 6 glucoproteínas plaquetarias diferentes. Se ha descrito que estos antígenos pueden estimular la producción de aloanticuerpos una vez expuestos a plaquetas humanas con diferentes HPA, lo que provoca complicaciones clínicas como la trombocitopenia neonatal aloinmune y la púrpura postransfusional. Métodos: Se realizó el estudio a 11 muestras de pacientes en espera de trasplante renal de genotipo de los antígenos HPA-1,2,3 a/b mediante PCR multiplex, mientras que para el estudio de genotipo de los antígenos HPA-5a/b se utilizó la técnica de PCR con secuencia específica de primer. Los productos de ADN amplificados fueron visualizados mediante electroforesis en gel de agarosa y electroforesis capilar. Resultados: El análisis de los fragmentos de ADN amplificados revelaron resultados similares por ambos métodos. Para los antígenos HPA-1,-2, el 63 por ciento de las muestras fueron homocigóticas para el fenotipo (a) mientras que se observó heterocigocidad en todos los casos para el genotipo HPA-3. En el sistema HPA-5, el 54 por ciento fueron homocigóticas para el fenotipo (a) y el 46 por ciento, heterocigóticas. Para el genotipo del HPA-15, el 4 por ciento fueron homocigóticas para el fenotipo (b) mientras que el 96 por ciento resultaron ser heterocigóticas. Conclusiones: Estos resultados muestran similitudes para los genotipos HPA 1, 2,3 a/b, HPA 5a/b y HPA15 a/brespecto a lo planteado en la literatura(AU)

Introduction: Human platelet antigens (HPA) are expressed in 6 different platelet glycoproteins. It has been described that these antigens can stimulate the production of alloantibodies once exposed to human platelets with different HPA, which causes clinical complications such as neonatal alloimmune thrombocytopenia and postransfusional purpura. Methods: The study was performed on 11 samples of patients awaiting kidney transplantation of genotype of the HPA-1,2,3 a/b antigens by multiplex PCR, while for the genotype study of the HPA-5a/b antigens was used the PCR technique with primer-specificsequence. The amplified DNA products were visualized by agarose gel electrophoresis and by capillary electrophoresis. Results: The analysis of DNA fragments amplified by agarose electrophoresis and capillary electrophoresis revealed similar results in both methods. For the HPA-1, -2 antigens, 63 percent of the samples were homozygous for phenotype (a) while heterozygosity was observed in all cases for the HPA-3 genotype. In the HPA-5 system, 54 percent were homozygous for the phenotype (a) and 46 percent were heterozygous. For the genotype of HPA-15, 4 percent were homozygous for phenotype (b) while 96 percent proved heterozygous. Conclusions: These results show similarities for the genotypes HPA 1, 2.3 a/b, HPA 5a/b and HPA15 a/bwith respect to report in literature(AU)

Two novel mutations in exon 3 of PHOX2B gene: think about congenital central hypoventilation syndrome in patients with Hirschsprung disease.

BACKGROUND: Congenital central hypoventilation syndrome (CCHS) is characterized by alveolar hypoventilation increasing during sleep and affected patients are unable to perceive and respond to hypercarbia with increased ventilation and arousal during sleep. PHOX2B gene mutations are considered as responsible for CCHS. Most of patients with CCHS are heterozygous for polyalanine expansion mutations (PARMs) in exon 3, but 10% of patients with classic CCHS are heterozygous for non-polyalanine expansion mutations (NPARMs) of the PHOX2B gene. METHODS: Data are collected on 3 patients affected by CCHS who referred to the Paediatric Pulmonology Unit of Bambino Gesù Children's Hospital (Rome, Italy) for a multidisciplinary follow-up program between 2000 and 2017. RESULTS: We describe three cases of patients affected by CCHS for which two novel mutations on exon 3 of PHOX2B gene were detected. CONCLUSIONS: The description of these novel mutations and related clinical phenotypes allows to expand the knowledge into NPARM spectrum. Since the presence of Hirschsprung disease is related to NPARMs and the number of alanine repeats, we suggest performing CCHS genetic investigation and periodical assessment also in patients without a clear history of CCHS but affected by Hirschsprung disease. TRIAL REGISTRATION: Data are retrospectively collected.

Novel data on growth phenotype and causative genotypes in 29 patients with Morquio (Morquio-Brailsford) syndrome from Central-Eastern Europe.

Mucopolysaccharidosis type IVA, also known as Morquio (Morquio-Brailsford) syndrome results from accumulation of keratan sulfate (KS) and chondroitin-6-sulfate (C6S), whereas the primary cause is mutations in the gene encoding galactosamine (N-acetyl)-6-sulfatase (GALNS). Phenotypically it seems to be a well-defined condition, with two main clinical forms: mild (attenuated) and severe, which are determined based on a combination of symptoms, i.e., enzymatic activity of GALNS, age of onset, and symptom severity. Nevertheless, the natural history of MPSIVA in relation to specific anthropometric parameters (growth, head circumference, body proportions, and face phenotype) is not precisely characterized. The aim of our work was to analyze the aforementioned anthropometric parameters, including correlation to molecular data (causative GALNS mutations).

Caracterização genético-clínica de pacientes com fenilcetonúriano Estado de Alagoas / Genetic and clinical characterization of patients with phenylketonuria in Alagoas state, Brazil

Objetivos: Caracterizar o perfil genético-clínico de pacientes com fenilcetonúria em Alagoas, diagnosticados e acompanhados pelo Programa Nacional de Triagem Neonatal.Métodos: Pacientes com fenilcetonúria, assistidos pelo Serviço de Referência em Triagem Neonatal de Alagoas, foram submetidos a coleta de sangue para rastrear mutações genéticas determinantes da variação fenotípica da doença. Concomitantemente, os pacientes ou seus responsáveis responderam a um questionário padronizado para coleta de dados clínicos e epidemiológicos.Resultados: Foram acompanhados 20 pacientes, sendo 14 do sexo masculino e seis do sexo feminino, pertencentes a 18 famílias. A idade dos pacientes estudados variou de 3 a 31 anos. Houve consanguinidade parental em 3/18 famílias; recorrência familial 3/18; 3/20 tiveram diagnóstico tardio; 2/20 interromperam temporariamente o tratamento; 1/20 não aderiu ao tratamento; e 6/20 apresentam manifestações clínicas. A análise das mutações foi concluída em 15/20 pacientes. As mutações encontradas no gene da fenilalanina hidroxilase foram: R261Q-homozigose (2 pacientes); V388M/I65T (1); R270K/V388M (1); I65T/L348V (1); IVS10nt11G>A-homozigose (2); V388M/R252W (1); R261Q/I65T (1); IVS10nt11G>A/R252W (1); V388M/IVS10nt11G>A (3); R261Q/R252W (1); R261Q/V388M (1).Conclusões: O genótipo V388M/IVS10nt11G>A foi o mais prevalente. Trinta por cento dos pacientes foram sintomáticos, provavelmente pela natureza das mutações, não adesão ao tratamento, tratamento inadequado e/ou diagnóstico tardio.

Aims: Characterizing the genetic/clinical profile of patients diagnosed with Phenylketonuria in Alagoas, monitored by the National Program of Newborn Screening. Methods: Patients with phenylketonuria, assisted by the Reference Center for Neonatal Screening of Alagoas , underwent blood sampling for detecting genetic determinants for the phenotypic variability of the disease. Concomitantly, patients or their guardians answered a standardized questionnaire for collection of clinical and epidemiological data. Results: Twenty patients (14 males and 6 females), belonging to 18 families, were monitored. Age ranged from 3-31 (mean age 10.35).We found parental consanguinity in 3/18 families; familial recurrence was 3/18; 3/20 had late diagnosis; 2/20 interrupted treatment for some time; 1/20 did not adhere to treatment; and 6/20 had clinical manifestations. Analysis of mutations was concluded in 15/20 patients. Mutations found in the phenylalanine hydroxylase gene were: R261Q-homozygous (2 patients); V388M/I65T (1); R270K/V388M (1); I65T/L348V (1); IVS10nt11G>A-homozygous(2); V388M/R252W (1); R261Q/I65T (1); IVS10nt11G>A/R252W (1); V388M/IVS10nt11G>A (3); R261Q/R252W (1); R261Q/V388M (1).

Lipodistrofia parcial familiar do tipo Dunnigan: atenção ao diagnóstico precoce / Dunnigan-type familial partial lipodystrophy: attention to precocious diagnosis

A lipodistrofia parcial familiar tipo Dunnigan é uma doença autossômica dominante rara. Em sua forma clássica, é resultante de uma mutação missense heterozigótica no gene LMNA, que codifica a proteína nuclear denominada lâmina tipo A/C. Caracteriza-se pelo desaparecimento progressivo do tecido adiposo subcutâneo nos membros, região glútea, abdome e tronco, que se inicia na puberdade, acompanhado de acúmulo de gordura em outras áreas, como a face, queixo, grandes lábios e região intra-abdominal, conferindo o aspecto de hipertrofia muscular e simulando o fenótipo de síndrome de Cushing. Mulheres afetadas são particularmente predispostas à resistência à insulina e suas complicações, incluindo sinais da síndrome dos ovários policísticos. Com o objetivo de alertar para o diagnóstico precoce, que possibilita a adoção de medidas que minimizam os graves distúrbios metabólicos vinculados à desordem, relatamos o caso de uma paciente em que a investigação foi realizada somente ao final da quinta década de vida. A aparente hipertrofia muscular e o acentuado depósito de gordura nos grandes lábios possibilitam aos médicos ginecologistas a suspeita diagnóstica.

Dunnigan-type familial partial lipodystrophy (FPLD) is an autosomal dominant disease that results from heterozygous missense mutations in LMNA, the gene that encodes nuclear lamin A/C. FPLD is characterized by a progressive disappearance of subcutaneous adipose tissue in the limbs, gluteal region, abdomen and trunk, beginning at the time of or after puberty, and excessive amount of fat in the face, chin, labia majora, and intra-abdominal region, leading to a Cushingoid appearance and increased muscularity phenotype. Affected women are particularly predisposed to insulin resistance and its complications, including features of polycystic ovary syndrome. To emphasize the importance of an early FPLD diagnosis, which is necessary to prevent serious metabolic disturbances, we report a woman diagnosed at about 50 years of age. Increased muscularity and significant labia majora fat deposit made the diagnosis possible by gynecologists.