Tumour risks and genotype-phenotype correlations associated with germline variants in succinate dehydrogenase subunit genes , and .

Background: Germline pathogenic variants in / are the most frequent causes of inherited phaeochromocytomas/paragangliomas. Insufficient information regarding penetrance and phenotypic variability hinders optimum management of mutation carriers. We estimate penetrance for symptomatic tumours and elucidate genotype-phenotype correlations in a large cohort of / mutation carriers.

Long QT syndrome and left ventricular noncompaction in 4 family members across 2 generations with KCNQ1 mutation.

The association of long QT syndrome and left ventricular noncompaction is uncommon, with only a handful of previous reports, and only one reported case in association with a mutation in KCNQ1. Here we present genetic and phenotypic data for 4 family members across 2 generations who all have evidence of prolonged QT interval and left ventricular noncompaction in association with a pathogenic mutation in KCNQ1, and discuss the potential mechanisms of this association. In conclusion, we suggest that it may be helpful to consider looking for mutations in KCNQ1 in similar patients.

Histiocytoid cardiomyopathy and microphthalmia with linear skin defects syndrome: phenotypes linked by truncating variants in .

Variants in which encodes a structural component of complex I of the mitochondrial respiratory chain (MRC), were recently independently reported to cause histiocytoid cardiomyopathy (histiocytoid CM) and microphthalmia with linear skin defects syndrome (MLS syndrome). Here we report an additional case of histiocytoid CM, which carries a de novo nonsense variant in (ENST00000276062.8: c.

Diagnostic yield of molecular autopsy in patients with sudden arrhythmic death syndrome using targeted exome sequencing.

Aims: The targeted genetic screening of Sudden Arrhythmic Death Syndrome (SADS) probands in a molecular autopsy has a diagnostic yield of up to 35%. Exome sequencing has the potential to improve this yield. The primary aim of this study is to examine the feasibility and diagnostic utility of targeted exome screening in SADS victims, utilizing familial clinical screening whenever possible.

Obesity, Aspirin, and Risk of Colorectal Cancer in Carriers of Hereditary Colorectal Cancer: A Prospective Investigation in the CAPP2 Study.

Purpose: In the general population, increased adiposity is a significant risk factor for colorectal cancer (CRC), but whether obesity has similar effects in those with hereditary CRC is uncertain. This prospective study investigated the association between body mass index and cancer risk in patients with Lynch syndrome (LS).

Patients And Methods: Participants with LS were recruited to the CAPP2 study, in which they were randomly assigned to receive aspirin 600 mg per day or aspirin placebo, plus resistant starch 30 g per day or starch placebo (2 × 2 factorial design).

Monoallelic and biallelic mutations in MAB21L2 cause a spectrum of major eye malformations.

We identified four different missense mutations in the single-exon gene MAB21L2 in eight individuals with bilateral eye malformations from five unrelated families via three independent exome sequencing projects. Three mutational events altered the same amino acid (Arg51), and two were identical de novo mutations (c.151C>T [p.

Novel SCN5A mutation in amiodarone-responsive multifocal ventricular ectopy-associated cardiomyopathy.

Background: Mutations in SCN5A, which encodes the cardiac sodium channel NaV1.5, typically cause ventricular arrhythmia or conduction slowing. Recently, SCN5A mutations have been associated with heart failure combined with variable atrial and ventricular arrhythmia.

Long-term effect of resistant starch on cancer risk in carriers of hereditary colorectal cancer: an analysis from the CAPP2 randomised controlled trial.

Background: Observational studies report that higher intake of dietary fibre (a heterogeneous mix including non-starch polysaccharides and resistant starches) is associated with reduced risk of colorectal cancer, but no randomised trials with prevention of colorectal cancer as a primary endpoint have been done. We assessed the effect of resistant starch on the incidence of colorectal cancer.

Methods: In the CAPP2 study, individuals with Lynch syndrome were randomly assigned in a two-by-two factorial design to receive 600 mg aspirin or aspirin placebo or 30 g resistant starch or starch placebo, for up to 4 years.

Long-term effect of aspirin on cancer risk in carriers of hereditary colorectal cancer: an analysis from the CAPP2 randomised controlled trial.

Background: Observational studies report reduced colorectal cancer in regular aspirin consumers. Randomised controlled trials have shown reduced risk of adenomas but none have employed prevention of colorectal cancer as a primary endpoint. The CAPP2 trial aimed to investigate the antineoplastic effects of aspirin and a resistant starch in carriers of Lynch syndrome, the major form of hereditary colorectal cancer; we now report long-term follow-up of participants randomly assigned to aspirin or placebo.

Molecular analysis of pheochromocytoma after maternal transmission of SDHD mutation elucidates mechanism of parent-of-origin effect.

Context: Pheochromocytoma/paraganglioma occurs almost exclusively after paternal transmission of succinate dehydrogenase D (SDHD) mutations. This parent-of-origin effect has not been fully explained but is accompanied by obligate loss of the maternal copy of chromosome 11. Loss of wild-type SDHD and an additional imprinted gene (hypothesized to be H19) appears necessary for tumor formation.

Mutations in GATA2 cause primary lymphedema associated with a predisposition to acute myeloid leukemia (Emberger syndrome).

We report an allelic series of eight mutations in GATA2 underlying Emberger syndrome, an autosomal dominant primary lymphedema associated with a predisposition to acute myeloid leukemia. GATA2 is a transcription factor that plays an essential role in gene regulation during vascular development and hematopoietic differentiation. Our findings indicate that haploinsufficiency of GATA2 underlies primary lymphedema and predisposes to acute myeloid leukemia in this syndrome.

Clinical features and respiratory complications in Myhre syndrome.

We describe the clinical characteristics of 4 singleton cases, 3 males and 1 female, with Myhre Syndrome (OMIM 139210), who were born to non-consanguineous parents. Three cases had no family history of similarly affected individuals but 1 male's mother had short stature, some facial features suggestive of Myhre syndrome and evidence of skewed X-chromosome inactivation in her blood DNA. Short stature, deafness, learning difficulties, skeletal anomalies and facial dysmorphisms were evident in all cases.

Diagnostic use of skeletal survey in suspected skeletal dysplasia.

Objective: To review the practice of skeletal surveys in cases of suspected skeletal dysplasia.

Methods: Retrospective review of records of patients with suspected skeletal dysplasia between December 1997 and December 2005.

Results: A diagnosis of a specific skeletal dysplasia was reached in 155 out of a total of 285 suspected cases (54%).

Emberger syndrome-primary lymphedema with myelodysplasia: report of seven new cases.

Four reports have been published on an association between acute myeloid leukaemia (AML) and primary lymphedema, with or without congenital deafness. We report seven new cases, including one extended family, confirming this entity as a genetic syndrome. The lymphedema typically presents in one or both lower limbs, before the hematological abnormalities, with onset between infancy and puberty and frequently affecting the genitalia.

Novel features in auriculo-condylar syndrome.

Auriculo-condylar syndrome (ACS, OMIM 602483) is an autosomal dominant condition with marked phenotypic variability. In some patients, the condition may be limited to the auricular deformity which can vary from auricular cleft, cupped helix to the 'question mark' ear, where there is constriction between the middle and lower thirds of the ear. The latter has also been reported in isolation.

X-linked cataract and Nance-Horan syndrome are allelic disorders.

Nance-Horan syndrome (NHS) is an X-linked developmental disorder characterized by congenital cataract, dental anomalies, facial dysmorphism and, in some cases, mental retardation. Protein truncation mutations in a novel gene (NHS) have been identified in patients with this syndrome. We previously mapped X-linked congenital cataract (CXN) in one family to an interval on chromosome Xp22.

Andersen-Tawil syndrome.

Advances in the understanding of genetic aspects of cardiovascular diseases, together with an increase in the availability of genetic analysis, have resulted in not only increased diagnosis of known inherited conditions, but also the identification of novel syndromes. The combination of potassium-sensitive periodic paralysis, ventricular arrhythmias and dysmorphism, initially described by Andersen and Tawil, represents such a novel condition. We report a case in which genetic analysis led to the diagnosis of Andersen-Tawil syndrome after 15 years of protracted non-invasive and invasive investigations from initial presentation to ultimate diagnosis in a young female.

A recurrent 15q13.3 microdeletion syndrome associated with mental retardation and seizures.

We report a recurrent microdeletion syndrome causing mental retardation, epilepsy and variable facial and digital dysmorphisms. We describe nine affected individuals, including six probands: two with de novo deletions, two who inherited the deletion from an affected parent and two with unknown inheritance. The proximal breakpoint of the largest deletion is contiguous with breakpoint 3 (BP3) of the Prader-Willi and Angelman syndrome region, extending 3.

Clinical presentation and penetrance of pheochromocytoma/paraganglioma syndromes.

Context: The identification of mutations in genes encoding peptides of succinate dehydrogenase (SDH) in pheochromocytoma/paraganglioma syndromes has necessitated clear elucidation of genotype-phenotype associations.

Objective: Our objective was to determine genotype-phenotype associations in a cohort of patients with pheochromocytoma/paraganglioma syndromes and succinate dehydrogenase subunit B (SDHB) or subunit D (SDHD) mutations.

Design, Setting, And Participants: The International SDH Consortium studied 116 individuals (83 affected and 33 clinically unaffected) from 62 families with pheochromocytoma/paraganglioma syndromes and SDHB or SDHD mutations.

Sequence changes in predicted promoter elements of STK11/LKB1 are unlikely to contribute to Peutz-Jeghers syndrome.

Background: Germline mutations or large-scale deletions in the coding region and splice sites of STK11/LKB1 do not account for all cases of Peutz-Jeghers syndrome (PJS). It is conceivable that, on the basis of data from other diseases, inherited variation in promoter elements of STK11/LKB1 may cause PJS.

Results: Phylogenetic foot printing and transcription factor binding site prediction of sequence 5' to the coding sequence of STK11/LKB1 was performed to identify non-coding sequences of DNA indicative of regulatory elements.

An audit of screening for familial breast cancer before 50 years in the South Thames Region - have we got it right?

We have carried out an audit of breast screening by mammography under 50 years of age in a cohort of 192 women attending family cancer clinics run by the South Thames genetic services. Of these women, six came from families in which a BRCA mutation had been identified, 61 had > 50%, 35 a 20-50% and 90 had < 20% chance of carrying a high risk mutation. In the 192 women in the screened cohort, 9 breast cancers were diagnosed (4.

Low-penetrance susceptibility to breast cancer due to CHEK2(*)1100delC in noncarriers of BRCA1 or BRCA2 mutations.

Mutations in BRCA1 and BRCA2 confer a high risk of breast and ovarian cancer, but account for only a small fraction of breast cancer susceptibility. To find additional genes conferring susceptibility to breast cancer, we analyzed CHEK2 (also known as CHK2), which encodes a cell-cycle checkpoint kinase that is implicated in DNA repair processes involving BRCA1 and p53 (refs 3,4,5). We show that CHEK2(*)1100delC, a truncating variant that abrogates the kinase activity, has a frequency of 1.