Multiple copy number variants in a pediatric patient with Hb H disease and intellectual disability.

Two distinct syndromes that link α-thalassemia and intellectual disability (ID) have been described: ATR-X, due to mutations in the ATRX gene, and ATR-16, a contiguous gene deletion syndrome in the telomeric region of the short arm of chromosome 16. A critical region where the candidate genes for the ID map has been established. In a pediatric patient with Hemoglobin H disease, dysmorphic features and ID, 4 novel and clinically relevant Copy Number Variants were identified. PCR-GAP, MLPA and FISH analyses established the cause of the α-thalassemia. SNP-array analysis revealed the presence of 4 altered loci: 3 deletions (arr[hg19]Chr16(16p13.3; 88,165-1,507,988) x1; arr[hg19]Chr6(6p21.1; 44,798,701-45,334,537) x1 and arr[hg19]Chr17(17q25.3; 80,544,855-81,057,996) x1) and a terminal duplication (arr[hg19]Chr7(7p22.3-p22.2; 4,935-4,139,785) x3). The -α(3.7) mutation and the ∼1.51 Mb in 16p13.3 are involved in the alpha-thalassemic phenotype. However, the critical region for ATR-16 cannot be narrowed down. The deletion affecting 6p21.1 removes the first 2 exons and part of intron 2 of the RUNX2 gene. Although heterozygous loss of function mutations affecting this gene have been associated with cleidocranial dysplasia, the patient does not exhibit pathognomonic signs of this syndrome, possibly due to the fact that the isoform d of the transcription factor remains unaffected. This work highlights the importance of searching for cryptic deletions in patients with ID and reiterates the need of the molecular analysis when it is associated to microcytic hypochromic anemia with normal iron status.

Skeletal involvement in Gaucher disease: An observational multicenter study of prognostic factors in the Argentine Gaucher disease patients.

Patients with Gaucher type 1 (GD1) throughout Argentina were enrolled in the Argentine bone project to evaluate bone disease and its determinants. We focused on presence and predictors of bone lesions (BL) and their relationship to therapeutic goals (TG) with timing and dose of enzyme replacement therapy (ERT). A total of 124 patients on ERT were enrolled in a multi-center study. All six TG were achieved by 82% of patients: 70.1% for bone pain and 91.1% for bone crisis. However, despite the fact that bone TGs were achieved, residual bone disease was present in 108 patients on ERT (87%) at time 0. 16% of patients showed new irreversible BL (bone infarcts and avascular osteonecrosis) despite ERT, suggesting that they appeared during ERT or were not detected at the moment of diagnosis. We observed 5 prognostic factors that predicted a higher probability of being free of bone disease: optimal ERT compliance; early diagnosis; timely initiation of therapy; ERT initiation dose ≥45 UI/kg/EOW; and the absence of history of splenectomy. Skeletal involvement was classified into 4 major phenotypic groups according to BL: group 1 (12.9%) without BL; group 2 (28.2%) with reversible BL; group 3 (41.9%) with reversible BL and irreversible chronic BL; and group 4 (16.9%) with acute irreversible BL. Our study identifies prognostic factors for achieving best therapeutic outcomes, introduces new risk stratification for patients and suggests the need for a redefinition of bone TG. Am. J. Hematol. 91:E448-E453, 2016. © 2016 Wiley Periodicals, Inc.

Long-read single molecule real-time (SMRT) sequencing of GBA1 locus in Gaucher disease national cohort from Argentina reveals high frequency of complex allele underlying severe skeletal phenotypes: Collaborative study from the Argentine Group for Diagnosis and Treatment of Gaucher Disease.

Gaucher disease is reckoned for extreme phenotypic diversity that does not show consistent genotype/phenotype correlations. In Argentina, a national collaborative group, Grupo Argentino de Diagnóstico y Tratamiento de la Enfermedad de Gaucher, GADTEG, have delineated uniformly severe type 1 Gaucher disease manifestations presenting in childhood with large burden of irreversible skeletal disease. Here using Long-Read Single Molecule Real-Time (SMRT) Sequencing of GBA1 locus, we show that RecNciI allele is highly prevalent and associates with severe skeletal manifestations in childhood.

Clinical consequences of interrupting enzyme replacement therapy in children with type 1 Gaucher disease.

OBJECTIVE: To document the effects of interrupting enzyme replacement therapy (ERT) for at least 1 year in a group of children with type 1 Gaucher disease. STUDY DESIGN: All children with type 1 Gaucher disease who were treated at 2 pediatric centers and who were required to suspend ERT for at least 1 year were studied before, during, and after treatment interruption. Hemoglobin and platelet levels, organomegaly, growth, and bone manifestations were monitored. RESULTS: Five of 32 children experienced treatment interruptions. Before ERT, all children had splenomegaly, 4 children had hepatomegaly, 4 children had growth retardation, 3 children had skeletal manifestations, 3 children had thrombocytopenia, and 1 child had anemia. After 1 to 7 years of ERT, all children were growing normally, none had skeletal manifestations, organomegaly had decreased or disappeared, and hematologic features had improved. After 15 to 36 months of ERT interruption, splenomegaly recurred or worsened in all children, hepatomegaly and hematologic features recurred or worsened in 4 children, serious bone manifestations developed in 4 children, and 3 children experienced growth retardation. After at least 11 months of resumed ERT in 4 children, 2 had hepatomegaly, 2 had splenomegaly, and all had persistent skeletal manifestations. CONCLUSION: Interruption of ERT in children with type 1 Gaucher disease should be avoided because it can cause recurrent organomegaly, growth delays, and skeletal manifestations that do not resolve after treatment reinstatement.

Wiskott-Aldrich syndrome in Argentina: 17 unique, including nine novel, mutations.

Wiskott-Aldrich syndrome (WAS), is an X-linked immunodeficiency disease caused by mutations of the WAS protein (WASP) gene, characterized by thrombocytopenia, eczema and recurrent infections. X-linked thrombocytopenia (XLT) is a milder form with only platelet abnormalities. Cumulative mutation data have revealed that WASP genotypes are highly variable among WAS patients. By SSCP analysis, we determined the location of the mutation in 23 WAS patients from 17 unrelated families with variable clinical phenotypes. Direct sequence analysis of genomic DNA showed 9 novel mutations (Q52H, G70W, 393del7, Ex 7 Ex11del, IVS 8+1G-->C, 925delG, 959ins38, 1380del8, and IVS 2+2T-->C) and 8 known mutations distributed throughout the WAS gene. This is the first report of WAS gene mutations from a Latin American country.

Disqueratosis congénita: presentación de un caso clínico / Congenital dyskeratosis: a clinical report

La disqueratosis congénita o síndrome de Zinsser Egman Cole es una forma muy poco frecuente de dermatosis que se caracteriza por hiperpigmentación reticulada cutánea, distrofia de faneras, leucoplasia premaligna de la mucosa oral y pancitopenia progresiva. El objetivo de este trabajo fue la presentación de un paciente de sexo masculino, actualmente de 8 años, que consultó por anemia ferropénica, trastornos tróficos de piel y mucosas, leucoplasia severa de lengua y disfagia para sólidos semi sólidos, a quien se hizo diagnóstico inicial de síndrome de Plummer Vinson por la presencia de membranas esofágicas altas. La persistencia de la clínica con la aparición de hiperpigmentación reticulada en cuello y tronco y leucopenia progresiva hizo sospechar esta patología que fue confirmada por el estudio genético correspondiente