Deletion of conserved non-coding sequences downstream from NKX2-1: A novel disease-causing mechanism for benign hereditary chorea.

BACKGROUND: Benign hereditary chorea (BHC) is an autosomal dominant disorder characterized by early-onset non-progressive involuntary movements. Although NKX2-1 mutations or deletions are the cause of BHC, some BHC families do not have pathogenic alterations in the NKX2-1 gene, indicating that mutations of non-coding regulatory elements of NKX2-1 may also play a role. METHODS AND RESULTS: By using whole-genome microarray analysis, we identified a 117 Kb founder deletion in three apparently unrelated BHC families that were negative for NKX2-1 sequence variants. Targeted next generation sequencing analysis confirmed the deletion and showed that it was part of a complex local genomic rearrangement. In addition, we also detected a 648 Kb de novo deletion in an isolated BHC case. Both deletions are located downstream from NKX2-1 on chromosome 14q13.2-q13.3 and share a 33 Kb smallest region of overlap with six previously reported cases. This region has no gene but contains multiple evolutionarily highly conserved non-coding sequences. CONCLUSION: We propose that the deletion of potential regulatory elements necessary for NKX2-1 expression in this critical region is responsible for BHC phenotype in these patients, and this is a novel disease-causing mechanism for BHC.

Cutis marmorata telangiectatica congenita: a focus on its diagnosis, ophthalmic anomalies, and possible etiologic factors.

Purpose: Cutis marmorata telangiectatica congenita (CMTC) is a rare congenital disorder typified by localized or generalized cutaneous vascular anomalies, which dissipate over time. We review the diagnostic approach to CMTC and present a comprehensive examination of its ocular manifestations. Additionally, we offer recommendations for the ophthalmologic workup for patients with CMTC. Finally, we examine the possible causes of CMTC and summarize the current efforts to establish an etiologic mechanism for this disease.Methods: Thirty-three published cases of CMTC with ocular anomalies are examined in detail.Results: CMTC is diagnosed based on a specific set of congenital cutaneous symptoms, principally congenital reticular erythema that is unresponsive to local warming and absence of venectasia within the skin lesions. Ocular findings are not currently employed in this diagnostic process, likely due to an incomplete understanding into their presentation, frequency, and natural history. We show that the majority of ophthalmic manifestations are congenital, with glaucoma and posterior segment anomalies, consisting of retinal perfusion defects and vascular abnormalities, as the most frequently reported findings. Typical ophthalmic medical and surgical interventions appear to be effective for management of these CMTC-related pathology. Unfortunately, the etiology and pathophysiology of CMTC remains unknown, which obfuscates efforts to identify, examine, and initiate treatment in patients.Conclusions: While the ophthalmic community has traditionally viewed glaucoma as the classic ocular anomaly of CMTC, this dataset advocates for the prompt investigation of posterior segment abnormalities as well. However, our understanding of CMTC's ocular anomalies is complicated by a lack of reporting and/or incomplete (or nonexistent) ophthalmic examinations, and we strongly encourage comprehensive ophthalmic examinations for all CMTC patients at the time of diagnosis, followed by appropriate screening and surveillance throughout life. We believe these recommendations will spur additional data and disease insights that may be useful for future refinements to CMTC diagnostic algorithms.

Genetics of syndromic and nonsyndromic aortopathies.

PURPOSE OF REVIEW: To review the literature and provide a summary of management of syndromic and nonsyndromic aortopathies. RECENT FINDINGS: The number of newly identified genetic causes for aortopathies have continued to increase over the past 10 years. The number of reported individuals with most hereditary aneurysm genes is small but increasing with more publications focusing describing the natural history caused by each gene. SUMMARY: Aortopathy can present as an isolated finding or present as part of a larger genetic syndrome. Advances in genetic testing technology has shed light on the increasing importance of molecular diagnostics in the evaluation and management of patients with hereditary aortic disease. Molecular diagnostics and family phenotyping can aide in the diagnosis and management of pediatric patients with aortic disease.

Pathogenic variants in USP7 cause a neurodevelopmental disorder with speech delays, altered behavior, and neurologic anomalies.

PURPOSE: Haploinsufficiency of USP7, located at chromosome 16p13.2, has recently been reported in seven individuals with neurodevelopmental phenotypes, including developmental delay/intellectual disability (DD/ID), autism spectrum disorder (ASD), seizures, and hypogonadism. Further, USP7 was identified to critically incorporate into the MAGEL2-USP7-TRIM27 (MUST), such that pathogenic variants in USP7 lead to altered endosomal F-actin polymerization and dysregulated protein recycling. METHODS: We report 16 newly identified individuals with heterozygous USP7 variants, identified by genome or exome sequencing or by chromosome microarray analysis. Clinical features were evaluated by review of medical records. Additional clinical information was obtained on the seven previously reported individuals to fully elucidate the phenotypic expression associated with USP7 haploinsufficiency. RESULTS: The clinical manifestations of these 23 individuals suggest a syndrome characterized by DD/ID, hypotonia, eye anomalies,feeding difficulties, GERD, behavioral anomalies, and ASD, and more specific phenotypes of speech delays including a nonverbal phenotype and abnormal brain magnetic resonance image findings including white matter changes based on neuroradiologic examination. CONCLUSION: The consistency of clinical features among all individuals presented regardless of de novo USP7 variant type supports haploinsufficiency as a mechanism for pathogenesis and refines the clinical impact faced by affected individuals and caregivers.

Patient Decisions to Receive Secondary Pharmacogenomic Findings and Development of a Multidisciplinary Practice Model to Integrate Results Into Patient Care.

Whole exome sequencing (WES) has the potential of identifying secondary findings that are predictive of poor pharmacotherapy outcomes. The purpose of this study was to investigate patients' wishes regarding the reporting of secondary pharmacogenomic findings. WES results (n = 106 patients) were retrospectively reviewed to determine the number of patients electing to receive secondary pharmacogenomic results. Phenotypes were assigned based on Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines. The percent of patients with a predicted phenotype associated with a gene-based CPIC dosing recommendation was determined. Ninety-nine patients (93.4%) elected to receive secondary pharmacogenomic findings. For each gene-drug pair analyzed, the number of patients with an actionable phenotype ranged from two (2%) to 43 patients (43.4%). Combining all gene-drug pairs, 84 unique patients (84.8%) had an actionable phenotype. A prospective multidisciplinary practice model was developed for integrating secondary pharmacogenomic findings into clinical practice. Our model highlights a unique collaboration between physician-geneticists, pharmacists, and genetic counselors.

LOX Mutations Predispose to Thoracic Aortic Aneurysms and Dissections.

RATIONALE: Mutations in several genes have been identified that are responsible for 25% of families with familial thoracic aortic aneurysms and dissections. However, the causative gene remains unknown in 75% of families. OBJECTIVES: To identify the causative mutation in families with autosomal dominant inheritance of thoracic aortic aneurysms and dissections. METHODS AND RESULTS: Exome sequencing was used to identify the mutation responsible for a large family with thoracic aortic aneurysms and dissections. A heterozygous rare variant, c.839G>T (p.Ser280Arg), was identified in LOX, encoding a lysyl oxidase, that segregated with disease in the family. Sanger and exome sequencing was used to investigate mutations in LOX in an additional 410 probands from unrelated families. Additional LOX rare variants that segregated with disease in families were identified, including c.125G>A (p.Trp42*), c.604G>T (p.Gly202*), c.743C>T (p.Thr248Ile), c.800A>C (p.Gln267Pro), and c.1044T>A (p.Ser348Arg). The altered amino acids cause haploinsufficiency for LOX or are located at a highly conserved LOX catalytic domain, which is relatively invariant in the population. Expression of the LOX variants p.Ser280Arg and p.Ser348Arg resulted in significantly lower lysyl oxidase activity when compared with the wild-type protein. Individuals with LOX variants had fusiform enlargement of the root and ascending thoracic aorta, leading to ascending aortic dissections. CONCLUSIONS: These data, along with previous studies showing that the deficiency of LOX in mice or inhibition of lysyl oxidases in turkeys and rats causes aortic dissections, support the conclusion that rare genetic variants in LOX predispose to thoracic aortic disease.

Evolving Approaches to Genetic Evaluation of Specific Cardiomyopathies.

The understanding of the genetic basis of cardiomyopathy has expanded significantly over the past 2 decades. The increasing availability, shortening diagnostic time, and lowering costs of genetic testing have provided researchers and physicians with the opportunity to identify the underlying genetic determinants for thousands of genetic disorders, including inherited cardiomyopathies, in effort to improve patient morbidities and mortality. As such, genetic testing has advanced from basic scientific research to clinical application and has been incorporated as part of patient evaluations for suspected inherited cardiomyopathies. Genetic evaluation framework of inherited cardiomyopathies typically encompasses careful evaluation of family history, genetic counseling, clinical screening of family members, and if appropriate, molecular genetic testing. This review summarizes the genetics, current guideline recommendations, and evidence supporting the genetic evaluation framework of five hereditary forms of cardiomyopathy: dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), arrhythmogenic right ventricular cardiomyopathy (ARVC), restrictive cardiomyopathy (RCM), and left ventricular noncompaction (LVNC).

USP7 Acts as a Molecular Rheostat to Promote WASH-Dependent Endosomal Protein Recycling and Is Mutated in a Human Neurodevelopmental Disorder.

Endosomal protein recycling is a fundamental cellular process important for cellular homeostasis, signaling, and fate determination that is implicated in several diseases. WASH is an actin-nucleating protein essential for this process, and its activity is controlled through K63-linked ubiquitination by the MAGE-L2-TRIM27 ubiquitin ligase. Here, we show that the USP7 deubiquitinating enzyme is an integral component of the MAGE-L2-TRIM27 ligase and is essential for WASH-mediated endosomal actin assembly and protein recycling. Mechanistically, USP7 acts as a molecular rheostat to precisely fine-tune endosomal F-actin levels by counteracting TRIM27 auto-ubiquitination/degradation and preventing overactivation of WASH through directly deubiquitinating it. Importantly, we identify de novo heterozygous loss-of-function mutations of USP7 in individuals with a neurodevelopmental disorder, featuring intellectual disability and autism spectrum disorder. These results provide unanticipated insights into endosomal trafficking, illuminate the cooperativity between an ubiquitin ligase and a deubiquitinating enzyme, and establish a role for USP7 in human neurodevelopmental disease.

Granulomatous disease associated with NOD2 sequence variants and familial camptodactyly: An intermediate form of NOD2-associated diseases?

OBJECTIVE: Nucleotide-binding oligomerization domain-containing protein-2 (NOD2)-associated diseases may be a spectrum of disease. We report two families who exhibited an intermediate form of Blau syndrome and NOD2-associated autoinflammatory disease (NAID). METHODS: We identified two families with granulomatous disease. The clinical phenotypes and genotypes of these two families were reviewed and analyzed. RESULTS: The proband in family 1 was a white 57-year-old woman, with camptodactyly (age 6 years), inflammatory polyarthritis and dermatitis (age of 30 years), and cough, dyspnea, dry eyes, parotid gland enlargement, and fever. A computerized tomography showed mediastinal lymphadenopathy without hilar involvement, and a mediastinal lymph node biopsy revealed non-caseating granuloma. Pedigree analysis suggested autosomal dominant inheritance, and genetic testing identified a NOD2 sequence variant IVS8(+158). The proband in family 2 was a white 50-year-old woman with inflammatory polyarthritis and periarticular subcutaneous nodules. Skin biopsy showed non-necrotizing granuloma. There was a family history of camptodactyly, and genetic testing identified a NOD2 sequence variant R703C. CONCLUSIONS: Both probands had granulomatous disease and autosomal dominant phenotype of familial camptodactyly coupled with the presence of the NOD2 sequence variants, IVS8(+158), and R703C. Granulomatous disease associated with NOD2 variants may be an intermediate form between Blau syndrome and NAID.

Systemic connective tissue features in women with fibromuscular dysplasia.

Fibromuscular dysplasia (FMD) is a non-atherosclerotic disease associated with hypertension, headache, dissection, stroke, and aneurysm. The etiology is unknown but hypothesized to involve genetic and environmental components. Previous studies suggest a possible overlap of FMD with other connective tissue diseases that present with dissections and aneurysms. The aim of this study was to investigate the prevalence of connective tissue physical features in FMD. A total of 142 FMD patients were consecutively enrolled at a single referral center (97.9% female, 92.1% of whom had multifocal FMD). Data are reported for 139 female patients. Moderately severe myopia (29.1%), high palate (33.1%), dental crowding (29.7%), and early-onset arthritis (15.6%) were prevalent features. Classic connective features such as hypertelorism, cleft palate, and hypermobility were uncommon. The frequency of systemic connective tissue features was compared between FMD patients with a high vascular risk profile (having had ⩾1 dissection and/or ⩾2 aneurysms) and those with a standard vascular risk profile. A history of spontaneous pneumothorax (5.9% high risk vs 0% standard risk) and atrophic scarring (17.6% high risk vs 6.8% standard risk) were significantly more prevalent in the high risk group, p<0.05. High palate was observed in 43.1% of the high risk group versus 27.3% in the standard risk group, p=0.055. In conclusion, in a cohort of women with FMD, there was a prevalence of moderately severe myopia, high palate, dental crowding, and early-onset osteoarthritis. However, a characteristic phenotype was not discovered. Several connective tissue features such as high palate and pneumothorax were more prominent among FMD patients with a high vascular risk profile.

NOD2-associated autoinflammatory disease: a large cohort study.

OBJECTIVE: The aims of the study were to characterize the genotype profile of nucleotide-binding oligomerization domain containing 2 (NOD2)-associated autoinflammatory disease (NAID) and to report an extended study of the disease. METHODS: A total of 143 adult patients presented with clinical phenotypes suspicious for NAID and all were genotyped for NOD2 sequence variants. The genotype frequencies were compared between our cohort and literature reports. These patients were divided into two groups predicated on the presence or absence of NOD2 variants. RESULTS: Of the 143 patients, 67 (47%) carry NOD2 variants; the genotype frequency was significantly higher among our cohort than in the historical healthy controls. Fifty-four of the 67 carriers of NOD2 variants had NAID, which has a genotype profile that is somewhat different from Crohn's disease. All NAID patients were non-Jewish whites and 69% were women. The median age at onset was 33.5 years and the median disease duration at diagnosis was 10.7 years. NAID was sporadic in 93% of cases. Patients typically presented with periodic fever, dermatitis and inflammatory arthritis. As compared with the NOD2 variant-negative patients, the skin disease more typically manifested as erythematous patches or plaques on the trunk. Oligopolyarthritis/-arthralgia was common, with characteristic distal lower extremity swelling. Associated NOD2 variants were primarily IVS8(+158) or compound IVS8(+158) and R702W. CONCLUSION: This study underscores the NOD2 genotype association with NAID, which is a genetically complex multisystem disorder. It differs phenotypically from Crohn's disease with a distinct genotype profile. This disease may be more common than initially thought.

Prevalence of thoracic aortopathy in patients with juvenile Polyposis Syndrome-Hereditary Hemorrhagic Telangiectasia due to SMAD4.

Hereditary hemorrhagic telangiectasia (HHT) is characterized by abnormal vascular structures that may present as epistaxis, telangiectasias, and/or arteriovenous malformations. The genes associated with HHT (ACVRL1, ENG, and SMAD4) are members of the TGFß pathway. Other syndromes associated with abnormalities in TGFß signaling include Marfan syndrome, Loeys-Dietz syndrome and related disorders. These disorders have aortic disease as a prominent finding. While there are case reports of patients with HHT and aortopathy (dilatation/aneurysm, dissection, and rupture), this has not been systematically investigated. We conducted a retrospective chart review to determine the prevalence of aortopathy in an HHT cohort. Patients from a single institution were identified who met the Curacao Criteria for a clinical diagnosis of HHT and/or had a mutation in ACVRL1, ENG, or SMAD4 and underwent echocardiogram. Two-dimensional echocardiograms were reviewed by a single pediatric cardiologist, and data were collected on demographics, genotype, HHT features, aortic root measurements, past medical history, and family history. Z scores and nomograms were utilized to identify abnormal results. Twenty-six patients from 15 families (one ACVRL1, four ENG, eight SMAD4, and two clinical diagnoses) were included in the analysis. Aortopathy was found in 6/26 (23%) patients; all had SMAD4 mutations. In our cohort, 6/16 (38%) SMAD4 mutation carriers had evidence of aortopathy. These data suggest that aortopathy could be part of the spectrum of SMAD4-induced HHT manifestations. Routine aortic imaging, including measurements of the aorta, should be considered in patients with SMAD4 mutations to allow for appropriate medical and surgical recommendations.

Aortic Disease Presentation and Outcome Associated With ACTA2 Mutations.

BACKGROUND: ACTA2 mutations are the major cause of familial thoracic aortic aneurysms and dissections. We sought to characterize these aortic diseases in a large case series of individuals with ACTA2 mutations. METHODS AND RESULTS: Aortic disease, management, and outcome associated with the first aortic event (aortic dissection or aneurysm repair) were abstracted from the medical records of 277 individuals with 41 various ACTA2 mutations. Aortic events occurred in 48% of these individuals, with the vast majority presenting with thoracic aortic dissections (88%) associated with 25% mortality. Type A dissections were more common than type B dissections (54% versus 21%), but the median age of onset of type B dissections was significantly younger than type A dissections (27 years versus 36 years). Only 12% of aortic events were repair of ascending aortic aneurysms, which variably involved the aortic root, ascending aorta, and aortic arch. Overall, cumulative risk of an aortic event at age 85 years was 0.76 (95% confidence interval, 0.64-0.86). After adjustment for intrafamilial correlation, sex and race, mutations disrupting p.R179 and p.R258 were associated with significantly increased risk for aortic events, whereas p.R185Q and p.R118Q mutations showed significantly lower risk of aortic events compared with other mutations. CONCLUSIONS: ACTA2 mutations are associated with high risk of presentation with an acute aortic dissection. The lifetime risk for an aortic event is only 76%, suggesting that additional environmental or genetic factors play a role in expression of aortic disease in individuals with ACTA2 mutations.

MAT2A mutations predispose individuals to thoracic aortic aneurysms.

Up to 20% of individuals who have thoracic aortic aneurysms or acute aortic dissections but who do not have syndromic features have a family history of thoracic aortic disease. Significant genetic heterogeneity is established for this familial condition. Whole-genome linkage analysis and exome sequencing of distant relatives from a large family with autosomal-dominant inheritance of thoracic aortic aneurysms variably associated with the bicuspid aortic valve was used for identification of additional genes predisposing individuals to this condition. A rare variant, c.1031A>C (p.Glu344Ala), was identified in MAT2A, which encodes methionine adenosyltransferase II alpha (MAT IIα). This variant segregated with disease in the family, and Sanger sequencing of DNA from affected probands from unrelated families with thoracic aortic disease identified another MAT2A rare variant, c.1067G>A (p.Arg356His). Evidence that these variants predispose individuals to thoracic aortic aneurysms and dissections includes the following: there is a paucity of rare variants in MAT2A in the population; amino acids Glu344 and Arg356 are conserved from humans to zebrafish; and substitutions of these amino acids in MAT Iα are found in individuals with hypermethioninemia. Structural analysis suggested that p.Glu344Ala and p.Arg356His disrupt MAT IIα enzyme function. Knockdown of mat2aa in zebrafish via morpholino oligomers disrupted cardiovascular development. Co-transfected wild-type human MAT2A mRNA rescued defects of zebrafish cardiovascular development at significantly higher levels than mRNA edited to express either the Glu344 or Arg356 mutants, providing further evidence that the p.Glu344Ala and p.Arg356His substitutions impair MAT IIα function. The data presented here support the conclusion that rare genetic variants in MAT2A predispose individuals to thoracic aortic disease.

De novo mutations in the motor domain of KIF1A cause cognitive impairment, spastic paraparesis, axonal neuropathy, and cerebellar atrophy.

KIF1A is a neuron-specific motor protein that plays important roles in cargo transport along neurites. Recessive mutations in KIF1A were previously described in families with spastic paraparesis or sensory and autonomic neuropathy type-2. Here, we report 11 heterozygous de novo missense mutations (p.S58L, p.T99M, p.G102D, p.V144F, p.R167C, p.A202P, p.S215R, p.R216P, p.L249Q, p.E253K, and p.R316W) in KIF1A in 14 individuals, including two monozygotic twins. Two mutations (p.T99M and p.E253K) were recurrent, each being found in unrelated cases. All these de novo mutations are located in the motor domain (MD) of KIF1A. Structural modeling revealed that they alter conserved residues that are critical for the structure and function of the MD. Transfection studies suggested that at least five of these mutations affect the transport of the MD along axons. Individuals with de novo mutations in KIF1A display a phenotype characterized by cognitive impairment and variable presence of cerebellar atrophy, spastic paraparesis, optic nerve atrophy, peripheral neuropathy, and epilepsy. Our findings thus indicate that de novo missense mutations in the MD of KIF1A cause a phenotype that overlaps with, while being more severe, than that associated with recessive mutations in the same gene.

Family history of aortic disease predicts disease patterns and progression and is a significant influence on management strategies for patients and their relatives.

BACKGROUND: While a positive family history (FH) is a known risk factor for developing an aneurysm, its association with the extent of disease has not been established. We evaluated the influence of a FH of aortic disease with respect to the pattern and distribution of aortic aneurysms in a given patient. METHODS AND RESULTS: From November 1999 to November 2011, 1263 patients were enrolled in physician-sponsored endovascular device trials to treat aortic aneurysms. Of the 555 patients who were alive and returning for follow-up, we obtained 426 (77%) family histories. Three-dimensional imaging studies were used to identify the presence of aneurysms; 36% (155/426) of patients had a FH of aortic aneurysms and 5% (21/155) had isolated intracranial aneurysms. A logistic regression model was used to compare aortic morphology between patients with a positive or negative FH for aneurysms. Patients with a positive FH of aortic aneurysms were younger at their initial aneurysm (63 vs 70 years; P < .0001), more frequently had proximal aortic involvement (root: odds ratio [OR], 5.4; P < .0001; ascending: OR, 2.9; P < .001; thoracic: OR, 2.2; P = .01) with over 50% of FH patients ultimately developing suprarenal aortic involvement (P = .0001) and had a greater incidence of bilateral iliac artery aneurysm (OR, 1.8; P = .03). CONCLUSIONS: FH is an important tool that provides insight into the expected behavior of the untreated aorta and has significant implications for the development of treatment strategies. These findings should be used to guide patient's management with regard to treatment, follow-up paradigms, genetic testing, and screening of other family members.

Treatment of a patient with vertebral and subclavian aneurysms in the setting of a TGFBR2 mutation.

We present the case of a patient diagnosed with hypermobile Ehlers-Danlos syndrome with aneurysms of the subclavian and vertebral arteries. Molecular testing demonstrated transforming growth factor-beta receptor type 2 mutation. She was not a candidate for an open repair; therefore, a hybrid approach involving right vertebral ligation and bypass from the right common carotid to the vertebral C1-2 interface, endovascular exclusion of the left vertebral artery, and stent grafting of the left subclavian/axillary artery was used. The left vertebral embolization proved ineffective, requiring a right-to-left vertebral catheterization with glue occlusion. Based on her proper molecular diagnosis, she underwent prophylactic root and ascending aortic repair.

Midterm results of David reimplantation in patients with connective tissue disorder.

BACKGROUND: Few series have examined follow-up risks of the David reimplantation operation in patients with connective tissue disorder. Hence, we assessed its midterm safety and effectiveness for Marfan syndrome and other connective tissue disorders, such as Ehlers-Danlos, Loeys-Dietz, and marfanoid syndromes. METHODS: Of 313 patients who underwent modified David reimplantation, 178 identified as having connective tissue disorders underwent operation from January 1, 1991, to December 31, 2010. These disorders included Marfan (84%), marfanoid (8.4%), Loeys-Dietz (5.6%), Ehlers-Danlos (1.1%), and other syndromes (1.1%). Concomitant procedures included mitral valve repair in 7.3% and an atrial fibrillation procedure in 3.4%. RESULTS: There were no operative or 30-day deaths. Complications included prolonged ventilation (3%), renal failure (3%), reoperation for bleeding (2.2%), and permanent stroke (0.56%). Eight-year survival was 94% and freedom from aortic valve reoperation at 6 years was 92%. Of the 7 aortic valve reoperations, 3 were attributable to endocarditis and 3 to technical failure. One reoperation was performed at another hospital, and the reason could not be determined. There were no late strokes or hemorrhagic events. At 4 years, approximately 70% of patients had no aortic valve regurgitation, and 18% were in grade 1+. CONCLUSIONS: Prophylactic root and valve preservation using David reimplantation is safe and provides excellent midterm effectiveness and low risk of late events except for endocarditis.