A Novel Frameshift COL3A1 Variant in Vascular Ehlers-Danlos Syndrome.

Ehlers-Danlos syndromes (EDSs) are a group of heritable connective tissue disorders with distinct genetic etiologies. Of the 13 currently recognized types of EDS, the vascular type EDS (vEDS) is generally considered the most severe and is associated with a decreased life expectancy due to spontaneous arterial, intestinal, and or uterine rupture. Diagnosis of vEDS is supported by genetic testing confirming the presence of pathogenic variations in COL3A1, a type III procollagen gene. Management of vEDS is usually conservative with control of hemodynamic stress, frequent cardiovascular imaging, and, if indicated, a thoughtful endovascular intervention or surgical repair. We present a novel frameshift variant in COL3A1 leading to vEDS with multiple vascular involvements. Based on our literature review, this variant has not been reported and may result in a less severe form of vEDS. Our case report provides insight into genetic variants and clinical expression of vEDS.

Actionable exomic incidental findings in 6503 participants: challenges of variant classification.

Recommendations for laboratories to report incidental findings from genomic tests have stimulated interest in such results. In order to investigate the criteria and processes for assigning the pathogenicity of specific variants and to estimate the frequency of such incidental findings in patients of European and African ancestry, we classified potentially actionable pathogenic single-nucleotide variants (SNVs) in all 4300 European- and 2203 African-ancestry participants sequenced by the NHLBI Exome Sequencing Project (ESP). We considered 112 gene-disease pairs selected by an expert panel as associated with medically actionable genetic disorders that may be undiagnosed in adults. The resulting classifications were compared to classifications from other clinical and research genetic testing laboratories, as well as with in silico pathogenicity scores. Among European-ancestry participants, 30 of 4300 (0.7%) had a pathogenic SNV and six (0.1%) had a disruptive variant that was expected to be pathogenic, whereas 52 (1.2%) had likely pathogenic SNVs. For African-ancestry participants, six of 2203 (0.3%) had a pathogenic SNV and six (0.3%) had an expected pathogenic disruptive variant, whereas 13 (0.6%) had likely pathogenic SNVs. Genomic Evolutionary Rate Profiling mammalian conservation score and the Combined Annotation Dependent Depletion summary score of conservation, substitution, regulation, and other evidence were compared across pathogenicity assignments and appear to have utility in variant classification. This work provides a refined estimate of the burden of adult onset, medically actionable incidental findings expected from exome sequencing, highlights challenges in variant classification, and demonstrates the need for a better curated variant interpretation knowledge base.

Endovascular Repair of Internal Mammary Artery Aneurysms in 2 Sisters with SMAD3 Mutation.

True aneurysms of the internal mammary artery are rare and have been described in association with vasculitis or connective tissue disorders. Herein, we describe 2 cases of familial internal mammary artery aneurysms (IMAs) in 2 sisters with SMAD3 mutation. The older sister presented at the age of 54 years with an incidental diagnosis of a multilobed right IMA and the younger sister presented several years earlier with a ruptured left IMA aneurysm at the age of 49 years. Both sisters had Debakey type I aortic dissections prior to the IMA aneurysm presentation. To our knowledge, this is the first time IMA aneurysms have been described in siblings with SMAD3 mutation. In our experience, endovascular repair is a feasible and safe treatment option. An assessment of the entire arterial tree is recommended in patients diagnosed with SMAD3 mutations.

The challenge of comprehensive and consistent sequence variant interpretation between clinical laboratories.

PURPOSE: Genetic testing has shifted from academic laboratories with expertise in specific genes to commercial laboratories that offer tests of a diverse array of genes. The purpose of this comparative study was to determine whether one academic laboratory's model of variant interpretation is similar to that of several commercial laboratories. METHODS: The Collagen Diagnostic Laboratory (CDL) received, over a 14-month period, 38 requests to interpret variants originally identified by an outside laboratory (OL). The interpretations by the OL and CDL were compared and discrepancies were assessed. RESULTS: Interpretations from the OL and CDL were concordant in 11 inquiries (29%); discrepancies were moderate in 11 instances (29%) and significant in 16 (42%). Factors that caused discrepancies included the following: (i) private data were not shared in a public database (n = 9); (ii) publicly available allele frequency data were not referenced and used as evidence (n = 5); and (iii) important aspects of protein structure and function were not taken into account (n = 13). CONCLUSION: Comprehensive interpretation of sequence variants depends on good functional tests and well-curated variant databases. Provision of clinical information to the clinical laboratory, mandatory submission of identified variants with phenotype data to common resources, and collaboration between clinical laboratories and recognized experts is likely to improve consistency in variant interpretation among clinical laboratories.Genet Med 18 1, 20-24.

Pregnancy-related deaths and complications in women with vascular Ehlers-Danlos syndrome.

PURPOSE: The purpose of this study was to characterize the nature and magnitude of pregnancy risks in women with vascular Ehlers-Danlos syndrome. METHODS: Pregnancy-related death rate was determined by a review of pedigrees of families with vascular Ehlers-Danlos syndrome. Maternal morbidity was characterized through semistructured interviews with women with vascular Ehlers-Danlos syndrome or their next of kin. RESULTS: Pregnancy-related deaths occurred in 30 of 565 deliveries (5.3%). There was no difference in Kaplan-Meier survival curves between parous versus nulliparous women with vascular Ehlers-Danlos syndrome. Interviews with 39 women indicated that 46% of deliveries were uncomplicated. The most common pregnancy-related complications were third-/fourth-degree lacerations (20%) and preterm delivery (19%). Life-threatening complications occurred in 14.5% of deliveries and included arterial dissection/rupture (9.2%), uterine rupture (2.6%), and surgical complications (2.6%). There were 5 maternal deaths in 76 deliveries (6.5%). CONCLUSION: The risk of pregnancy-related complications is increased in women with vascular Ehlers-Danlos syndrome compared with the general population; however, survival data indicate that pregnancy does not appear to affect overall mortality compared with nulliparous women with vascular Ehlers-Danlos syndrome. The data were insufficient to determine whether mode or timing of delivery influenced risk of complications. Women with vascular Ehlers-Danlos syndrome should be engaged in a shared decision-making process when contemplating pregnancy and pregnancy management.

FKBP14-related Ehlers-Danlos syndrome: expansion of the phenotype to include vascular complications.

Biallelic mutations in FKBP14 cause a recessive form of Ehlers-Danlos syndrome (EDS) characterized by progressive kyphoscoliosis, myopathy, and hearing loss. To date, four children and one adult with this condition have been reported. We recently identified a 42-year-old man with severe kyphoscoliosis, restrictive/obstructive lung disease, short stature, mild hearing loss, decreased muscle mass, and a dissection of the celiac artery at age 41. He also had complete occlusion of the superior mesenteric artery with compensatory flow through an enlarged and tortuous inferior mesenteric artery. He was homozygous for a previously identified FKBP14 mutation, c.362dupC, p.(Glu122Argfs*7). He had no mutations in COL3A1, ACTA2, TGFBR1, TGFBR2, or SMAD3. The FKBP14 mutations in our patient occurred on the same haplotype as others with this same mutation. Although one family member in a previous report was thought to have early vascular complications, it could not be confirmed that she had biallelic mutations in FKBP14. This report expands the phenotype of FKBP14-related EDS to include risk for vascular complications and also raises the question of whether the shared haplotype represents a risk allele or founder mutation.

Follow-up of carriers of BRCA1 and BRCA2 variants of unknown significance: variant reclassification and surgical decisions.

PURPOSE: : Approximately 5-10% of patients who undergo genetic testing of BRCA1 and BRCA2 receive a variant of unknown significance (VUS) result. The ambiguous nature of a VUS may increase difficulty in patient understanding and decision making regarding risk reduction and surveillance options, including cancer risk-reducing surgeries. VUS reclassification to benign or deleterious may occur in time; however, clinical decisions may need to be made expeditiously, and some patients may pursue irreversible treatments before VUS reclassification. METHODS: : We reviewed the surgical decisions of 107 women postdisclosure of a BRCA VUS result counseled at our institute between 1998 and 2009. CONCLUSION: : Among women receiving a BRCA VUS result at our center, 11 of 107 (10.3%) pursued cancer risk-reducing mastectomy and 22 of 107 (20.6%) pursued cancer risk-reducing bilateral salpingo-oophorectomy. Reclassification of VUS occurred up to 9 years after testing, and 5 of 22 (22.7%) women followed up for 8 or more years continue to have a VUS result. We discuss considerations for providers of genetic services to discuss with patients who receive a VUS result.

Neuronal migration disorders in microcephalic osteodysplastic primordial dwarfism type I/III.

Microcephalic osteodysplastic primordial dwarfism (MOPD) is a rare microlissencephaly syndrome, with at least two distinct phenotypic and genetic types. MOPD type II is caused by pericentrin mutations, while types I and III appear to represent a distinct entity (MOPD I/III) with variably penetrant phenotypes and unknown genetic basis. The neuropathology of MOPD I/III is little understood, especially in comparison to other forms of lissencephaly. Here, we report postmortem brain findings in an 11-month-old female infant with MOPD I/III. The cerebral cortex was diffusely pachygyric, with a right parietal porencephalic lesion. Histologically, the cortex was abnormally thick and disorganized. Distinct malformations were observed in different cerebral lobes, as characterized using layer-specific neuronal markers. Frontal cortex was severely disorganized and coated with extensive leptomeningeal glioneuronal heterotopia. Temporal cortex had a relatively normal 6-layered pattern, despite cortical thickening. Occipital cortex was variably affected. The corpus callosum was extremely hypoplastic. Brainstem and cerebellar malformations were also present, as well as old necrotic foci. Findings in this case suggest that the cortical malformation in MOPD I/III is distinct from other forms of pachygyria-lissencephaly.

Ehlers-Danlos syndrome: a showcase of conditions that lead to understanding matrix biology.

The Ehlers-Danlos syndromes (EDS) are genetically and clinically diverse disorders in which affected individuals share a number of physical characteristics, including joint hypermobility, skin extensibility, and tissue friability. Clinical investigations opened the door to identifying the biochemical and molecular etiologies of this diverse but overlapping group of disorders. In this article, we provide an overview of how these disorders inform our understanding of matrix biology, including the role of collagens (types I, III and V), proteoglycans and other proteins.

The genetic basis of DOORS syndrome: an exome-sequencing study.

BACKGROUND: Deafness, onychodystrophy, osteodystrophy, mental retardation, and seizures (DOORS) syndrome is a rare autosomal recessive disorder of unknown cause. We aimed to identify the genetic basis of this syndrome by sequencing most coding exons in affected individuals. METHODS: Through a search of available case studies and communication with collaborators, we identified families that included at least one individual with at least three of the five main features of the DOORS syndrome: deafness, onychodystrophy, osteodystrophy, intellectual disability, and seizures. Participants were recruited from 26 centres in 17 countries. Families described in this study were enrolled between Dec 1, 2010, and March 1, 2013. Collaborating physicians enrolling participants obtained clinical information and DNA samples from the affected child and both parents if possible. We did whole-exome sequencing in affected individuals as they were enrolled, until we identified a candidate gene, and Sanger sequencing to confirm mutations. We did expression studies in human fibroblasts from one individual by real-time PCR and western blot analysis, and in mouse tissues by immunohistochemistry and real-time PCR. FINDINGS: 26 families were included in the study. We did exome sequencing in the first 17 enrolled families; we screened for TBC1D24 by Sanger sequencing in subsequent families. We identified TBC1D24 mutations in 11 individuals from nine families (by exome sequencing in seven families, and Sanger sequencing in two families). 18 families had individuals with all five main features of DOORS syndrome, and TBC1D24 mutations were identified in half of these families. The seizure types in individuals with TBC1D24 mutations included generalised tonic-clonic, complex partial, focal clonic, and infantile spasms. Of the 18 individuals with DOORS syndrome from 17 families without TBC1D24 mutations, eight did not have seizures and three did not have deafness. In expression studies, some mutations abrogated TBC1D24 mRNA stability. We also detected Tbc1d24 expression in mouse phalangeal chondrocytes and calvaria, which suggests a role of TBC1D24 in skeletogenesis. INTERPRETATION: Our findings suggest that mutations in TBC1D24 seem to be an important cause of DOORS syndrome and can cause diverse phenotypes. Thus, individuals with DOORS syndrome without deafness and seizures but with the other features should still be screened for TBC1D24 mutations. More information is needed to understand the cellular roles of TBC1D24 and identify the genes responsible for DOORS phenotypes in individuals who do not have a mutation in TBC1D24. FUNDING: US National Institutes of Health, the CIHR (Canada), the NIHR (UK), the Wellcome Trust, the Henry Smith Charity, and Action Medical Research.

Phenotypic and genotypic analyses of genetic skin disease through the Online Mendelian Inheritance in Man (OMIM) database.

Despite unprecedented gains in genomic technologies and genotype resolution, there remain tremendous challenges in our ability to capture disease "phenomes." We propose a previously unreported method for deconvolving human disease into elemental features, thereby creating a third space that interacts with both the disease and genotypic spaces. Using cutaneous and noncutaneous clinical findings available through Johns Hopkins University's Online Mendelian Inheritance in Man (OMIM) database, we set out to deconstruct genetic skin disease (GSD) into its various components, to more fully explore the relationship between these features within the complex phenotypic space and to characterize the genotypic space within which these disorders exist. Using OMIM, we defined the current state of GSD as including 560 distinct disorders associated with 501 unique protein-encoding genes. The most common elemental skin features included [corrected] hair/nail phenotypes, while [corrected] the most common systemic features included those associated with developmental, musculoskeletal, and neurological systems. As a proof of principle, we focused on a single skin feature- café-au-lait macules-and partitioned the disease space into hierarchical groupings on the basis of this finding. Finally, functional analyses among GSD loci were mapped back to skin features, providing insights into pigmentary and auditory features. Phenotypic deconvolution provides a framework for analyzing medical disorders and can aid in the organization and elucidation of biological mechanisms related to human disease.