Epidemiology of Primary Immunodeficiency in Iceland.

Purpose: Primary immunodeficiencies (PID) are rare heterogeneous diseases. Little is known about the prevalence of PID in Iceland and no national registry exists. The aim of the study was to describe the epidemiology of PID in Iceland.

Clinical and genetic features of pediatric acute lymphoblastic leukemia in Down syndrome in the Nordic countries.

Background: Children with Down syndrome (DS) have an increased risk for acute lymphoblastic leukemia (ALL). Although previous studies have shown that DS-ALL differs clinically and genetically from non-DS-ALL, much remains to be elucidated as regards genetic and prognostic factors in DS-ALL.

Methods: To address clinical and genetic differences between DS-ALL and non-DS-ALL and to identify prognostic factors in DS-ALL, we ascertained and reviewed all 128 pediatric DS-ALL diagnosed in the Nordic countries between 1981 and 2010.

High modal number and triple trisomies are highly correlated favorable factors in childhood B-cell precursor high hyperdiploid acute lymphoblastic leukemia treated according to the NOPHO ALL 1992/2000 protocols.

Between 1992 and 2008, 713 high hyperdiploid acute lymphoblastic leukemias in children aged 1-15 years were diagnosed and treated according to the Nordic Society for Pediatric Hematology and Oncology acute lymphoblastic leukemia 1992/2000 protocols. Twenty (2.8%) harbored t(1;19), t(9;22), der(11q23), or t(12;21).

Paediatric B-cell precursor acute lymphoblastic leukaemia with t(1;19)(q23;p13): clinical and cytogenetic characteristics of 47 cases from the Nordic countries treated according to NOPHO protocols.

The translocation t(1;19)(q23;p13)/der(19)t(1;19) is a risk stratifying aberration in childhood B-cell precursor acute lymphoblastic leukaemia (BCP ALL) in the Nordic countries. We have identified 47 children/adolescents with t(1;19)/der(19)t(1;19)-positive BCP ALL treated on two successive Nordic Society of Paediatric Haematology and Oncology (NOPHO) protocols between 1992 and 2007 and have reviewed the clinical and cytogenetic characteristics of these cases, comprising 1·8% of all cases. The translocation was balanced in 15 cases (32%) and unbalanced in 29 cases (62%).

Clinical and cytogenetic features of a population-based consecutive series of 285 pediatric T-cell acute lymphoblastic leukemias: rare T-cell receptor gene rearrangements are associated with poor outcome.

Clinical characteristics and cytogenetic aberrations were ascertained and reviewed in a population-based consecutive series of 285 pediatric T-cell acute lymphoblastic leukemias (T-ALLs) diagnosed between 1992 and 2006 in the Nordic countries. Informative karyotypic results were obtained in 249 (87%) cases, of which 119 (48%) were cytogenetically abnormal. Most (62%) of the aberrant T-ALLs were pseudodiploid.

[Extremely low birthweight infants in Iceland 1991-95. Risk factors for perinatal and neonatal death].

Objective: Survival of extremely low birthweight infants with birthweight <1000 g (ELBW) has increased in recent years, parallel to decline in perinatal mortality rate. This study was part of a geographically defined national study on survival, health, development and longterm outcome of ELBW infants in Iceland 1991-95 focusing on infant and maternal health risk factors affecting infant survival.

Material And Methods: Information was collected from the National Birth Registry on births and survival of ELBW infants weighing 500-999 g born in Iceland 1991-95.

Outcome of ETV6/RUNX1-positive childhood acute lymphoblastic leukaemia in the NOPHO-ALL-1992 protocol: frequent late relapses but good overall survival.

The prognostic impact of t(12;21)(p13;q22) [ETV6/RUNX1 fusion] in paediatric acute lymphoblastic leukaemia (ALL) has been extensively debated, particularly with regard to the frequency of late relapses and appropriate treatment regimens. We have retrospectively collected 679 ALLs with known ETV6/RUNX1 status, as ascertained by fluorescence in situ hybridization or reverse-transcription polymerase chain reaction, treated according to the Nordic Society of Paediatric Haematology and Oncology -ALL-1992 protocol. The assigned risk groups/treatment modalities for the 171 (25%) patients with t(12;21)-positive ALLs were 74 (43%) standard risk, 71 (42%) intermediate risk and 26 (15%) high risk.

Cytogenetic patterns in ETV6/RUNX1-positive pediatric B-cell precursor acute lymphoblastic leukemia: A Nordic series of 245 cases and review of the literature.

Between 1992 and 2004, 1,140 children (1 to<15 years) were diagnosed with B-cell precursor acute lymphoblastic leukemia (ALL) in the Nordic countries. Of these, 288 (25%) were positive for t(12;21)(p13;q22) [ETV6/RUNX1]. G-banding analyses were successful in 245 (85%); 43 (15%) were karyotypic failures.

[Uniparental disomy of chromosome 11 in a patient with Beckwith-Wiedemann syndrome. First reported case in Iceland].

Beckwith-Wiedemann syndrome (BWS) is a generalized overgrowth condition as well as regional and organ overgrowth in newborn children. It includes an increased risk of certain embryonal tumours. The aetiology of BWS is complex as different genetic and epigenetic alterations at chromosome region 11p15.

A genetic contribution to inflammatory bowel disease in Iceland: a genealogic approach.

Background And Aims: Both genetic and environmental factors play a role in the development of Crohn's disease (CD) and ulcerative colitis (UC), collectively known as inflammatory bowel disease (IBD). The aim of this study was to estimate the genetic component in IBD in Iceland.

Methods: A population-based sample, representing everyone diagnosed with IBD in Iceland from 1950 to 1996, was studied using a computerized population-wide genealogic database.

Familial predisposition and cosegregation analysis of adult obstructive sleep apnea and the sudden infant death syndrome.

Previous studies suggest a familial link between adult obstructive sleep apnea syndrome (OSAS) and sudden infant death syndrome (SIDS). However, most of these studies were hampered by the availability of too few cases of SIDS to draw conclusions. To examine the familial nature of this association in Iceland, hospital-based lists of all patients who were diagnosed with OSAS (n = 2,350) and SIDS (n = 58) from 1979 to 1998 were used to separately determine the familial occurrence of OSAS and SIDS and to search for evidence of cosegregation of these conditions in Icelandic families, using a nationwide genealogy database.

Oral lichen planus has a high rate of TP53 mutations. A study of oral mucosa in icelanD.

Oral squamous cell carcinoma (OSCC) is a world-wide health problem. In addition to external exposure (smoking and alcohol), certain oral lesions may increase the risk of oral cancer (e.g.