Clinical and biological landscape of constitutional mismatch-repair deficiency syndrome: an International Replication Repair Deficiency Consortium cohort study.

Background: Constitutional mismatch repair deficiency (CMMRD) syndrome is a rare and aggressive cancer predisposition syndrome. Because a scarcity of data on this condition contributes to management challenges and poor outcomes, we aimed to describe the clinical spectrum, cancer biology, and impact of genetics on patient survival in CMMRD.

Methods: In this cohort study, we collected cross-sectional and longitudinal data on all patients with CMMRD, with no age limits, registered with the International Replication Repair Deficiency Consortium (IRRDC) across more than 50 countries.

"I just wanted more": Hereditary cancer syndromes patients' perspectives on the utility of circulating tumour DNA testing for cancer screening.

Hereditary cancer syndromes (HCS) predispose individuals to a higher risk of developing multiple cancers. However, current screening strategies have limited ability to screen for all cancer risks. Circulating tumour DNA (ctDNA) detects DNA fragments shed by tumour cells in the bloodstream and can potentially detect cancers early.

BRAT1-related disorders: phenotypic spectrum and phenotype-genotype correlations from 97 patients.

BRAT1 biallelic variants are associated with rigidity and multifocal seizure syndrome, lethal neonatal (RMFSL), and neurodevelopmental disorder associating cerebellar atrophy with or without seizures syndrome (NEDCAS). To date, forty individuals have been reported in the literature. We collected clinical and molecular data from 57 additional cases allowing us to study a large cohort of 97 individuals and draw phenotype-genotype correlations.

Hereditary ovarian cancer risk reduction: a retrospective evaluation of patient perspectives and service provision at a regional hereditary gynaecologic cancer clinic 2006-2016.

Background: Germline pathogenic variants in BRCA1/2 have been established in hereditary breast and ovarian cancer (HBOC) syndrome and result in significantly elevated lifetime risk of ovarian cancer. Risk reduction interventions are presently the only effective means of improving survival and specialized counselling clinics have been established as an effective means of aiding this population in navigating complex decisions surrounding these interventions. This study sought to evaluate patient perceptions of a specialized counselling clinic for patients with HBOC Syndrome and referral patterns to this clinic.

"Game Changer": Health Professionals' Views on the Clinical Utility of Circulating Tumor DNA Testing in Hereditary Cancer Syndrome Management.

Background: We explored health professionals' views on the utility of circulating tumor DNA (ctDNA) testing in hereditary cancer syndrome (HCS) management.

Materials And Methods: A qualitative interpretive description study was conducted, using semi-structured interviews with professionals across Canada. Thematic analysis employing constant comparison was used for analysis.

Universal access to genetic counseling for women with epithelial ovarian cancer in Nova Scotia: Evaluating a new collaborative care model.

Women with pathogenic variants in BRCA1/2 have a significantly increased lifetime risk of breast and ovarian cancers. The availability of genetic testing to identify BRCA1/2 carriers is imperative to disease prevention and treatment. We evaluated the effectiveness of a new collaborative care model in Nova Scotia, involving the integration of genetic counselors into tumor board rounds, reduction in time allotted for initial genetic counseling appointments from 60 to 45 min, and a standardized dictation template, to increase referral rate for genetic counseling.

Severe cryopyrin-associated periodic syndrome first characterized by early childhood-onset sensorineural hearing loss - Case report and literature review.

Infant-onset bilateral sensorineural hearing loss is a key presenting symptom of the autoinflammatory cryopyrin-associated periodic syndrome. Other symptoms include periodic fever, cold-induced urticaria-like rash, chronic aseptic meningitis, polyarticular arthralgias, and renal AA amyloidosis. Early recognition and treatment with interleukin-1 blockade are critical for preventing disabling or fatal complications.

A family segregating lethal neonatal coenzyme Q deficiency caused by mutations in COQ9.

Primary CoQ deficiency is a clinically and genetically heterogeneous, autosomal recessive disorder resulting from mutations in genes involved in the synthesis of coenzyme Q (CoQ). To date, mutations in nine proteins required for the biosynthesis of CoQ cause CoQ deficiency with varying clinical presentations. In 2009 the first patient with mutations in COQ9 was reported in an infant with a neonatal-onset, primary CoQ deficiency with multi-system disease.

Unusual mutation and phenocopy in the family of a young patient with acromegalic gigantism.

Unlabelled: Early-onset acromegaly causing gigantism is often associated with aryl-hydrocarbon-interacting receptor protein () mutation, especially if there is a positive family history. A15y male presented with tiredness and visual problems. He was 201 cm tall with a span of 217 cm.

The complex behavioral phenotype of 15q13.3 microdeletion syndrome.

Background: Chromosome 15q13.3 represents a hotspot for genomic rearrangements due to repetitive sequences mediating nonallelic homologous recombination. Deletions of 15q13.

Gastrointestinal Findings in the Largest Series of Patients With Hereditary Biallelic Mismatch Repair Deficiency Syndrome: Report from the International Consortium.

Objectives: Hereditary biallelic mismatch repair deficiency (BMMRD) is caused by biallelic mutations in the mismatch repair (MMR) genes and manifests features of neurofibromatosis type 1, gastrointestinal (GI) polyposis, and GI, brain, and hematological cancers. This is the first study to characterize the GI phenotype in BMMRD using both retrospective and prospective surveillance data.

Methods: The International BMMRD Consortium was created to collect information on BMMRD families referred from around the world.

Germline mutations in MAP3K6 are associated with familial gastric cancer.

Gastric cancer is among the leading causes of cancer-related deaths worldwide. While heritable forms of gastric cancer are relatively rare, identifying the genes responsible for such cases can inform diagnosis and treatment for both hereditary and sporadic cases of gastric cancer. Mutations in the E-cadherin gene, CDH1, account for 40% of the most common form of familial gastric cancer (FGC), hereditary diffuse gastric cancer (HDGC).

Five children with deletions of 1p34.3 encompassing AGO1 and AGO3.

Small RNAs (miRNA, siRNA, and piRNA) regulate gene expression through targeted destruction or translational repression of specific messenger RNA in a fundamental biological process called RNA interference (RNAi). The Argonaute proteins, which derive from a highly conserved family of genes found in almost all eukaryotes, are critical mediators of this process. Four AGO genes are present in humans, three of which (AGO 1, 3, and 4) reside in a cluster on chromosome 1p35p34.

Vitamin B12 deficiency with intrinsic factor antibodies in an infant with poor growth and developmental delay.

Vitamin B12 deficiency is very rare in infants and may lead to serious hematological and neurodevelopmental abnormalities. The present article describes a case involving a seven-month-old boy with severe vitamin B12 deficiency, likely caused by juvenile pernicious anemia, an entity rarely described. The child presented with feeding intolerance, poor growth and developmental delay.

Loss-of-function HDAC8 mutations cause a phenotypic spectrum of Cornelia de Lange syndrome-like features, ocular hypertelorism, large fontanelle and X-linked inheritance.

Cornelia de Lange syndrome (CdLS) is a multisystem genetic disorder with distinct facies, growth failure, intellectual disability, distal limb anomalies, gastrointestinal and neurological disease. Mutations in NIPBL, encoding a cohesin regulatory protein, account for >80% of cases with typical facies. Mutations in the core cohesin complex proteins, encoded by the SMC1A, SMC3 and RAD21 genes, together account for ∼5% of subjects, often with atypical CdLS features.

Further evidence for germline BAP1 mutations predisposing to melanoma and malignant mesothelioma.

We describe a new family with a novel germline BAP1 nonsense mutation, c.723T>G, which leads to a predicted truncated protein, p.Y241*, or nonsense-mediated decay of the BAP1 mRNA.

A novel rearrangement of occludin causes brain calcification and renal dysfunction.

Pediatric intracranial calcification may be caused by inherited or acquired factors. We describe the identification of a novel rearrangement in which a downstream pseudogene translocates into exon 9 of OCLN, resulting in band-like brain calcification and advanced chronic kidney disease in early childhood. SNP genotyping and read-depth variation from whole exome sequencing initially pointed to a mutation in the OCLN gene.

Phenotypic heterogeneity of genomic disorders and rare copy-number variants.

Background: Some copy-number variants are associated with genomic disorders with extreme phenotypic heterogeneity. The cause of this variation is unknown, which presents challenges in genetic diagnosis, counseling, and management.

Methods: We analyzed the genomes of 2312 children known to carry a copy-number variant associated with intellectual disability and congenital abnormalities, using array comparative genomic hybridization.

Left ventricular noncompaction and coronary artery fistula in an infant with deletion 22q11.2.

This report describes an infant presenting with deletion 22q11.2 in combination with left ventricular noncompaction and a coronary artery fistula. These two cardiac findings have rarely been reported in association with each other and have never been reported together in combination with deletion 22q11.

Successful outcome in pregnancy with arterial tortuosity syndrome.

Background: Arterial tortuosity syndrome is a rare, autosomal recessive, severe, connective tissue disorder caused by a mutation in the SLC2A10 gene. We describe the pregnancy and delivery with this high-risk connective tissue disorder involving generalized abnormalities of the vasculature.

Case: A woman with an undefined connective tissue disorder was referred for tertiary prenatal care.