American journal of medical genetics. Part C, Seminars in medical genetics
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Am J Med Genet C Semin Med Genet · Mar 2020
Review22q11.2 deletion syndrome and congenital heart disease.
The 22q11.2 deletion syndrome has an estimated prevalence of 1 in 4-6,000 livebirths. The phenotype varies widely; the most common features include: facial dysmorphia, hypocalcemia, palate and speech disorders, feeding and gastrointestinal disorders, immunodeficiency, recurrent infections, neurodevelopmental and psychiatric disorders, and congenital heart disease. Approximately 60-80% of patients have a cardiac malformation most commonly including a subset of conotruncal defects (tetralogy of Fallot, truncus arteriosus, interrupted aortic arch type B), conoventricular and/or atrial septal defects, and aortic arch anomalies. ⋯ New guidelines suggest screening for a 22q11.2 deletion in the patient with tetralogy of Fallot, truncus arteriosus, interrupted aortic arch type B, conoventricular septal defects as well as those with an isolated aortic arch anomaly. Early identification of a 22q11.2 deletion in the neonate or infant when other syndromic features may not be apparent allows for timely parental screening for reproductive counseling and anticipatory evaluation of cardiac and noncardiac features. Screening the at-risk child or adult allows for important age-specific clinical, neurodevelopmental, psychiatric, and reproductive issues to be addressed.
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Am J Med Genet C Semin Med Genet · Mar 2017
ReviewHypermobile Ehlers-Danlos syndrome (a.k.a. Ehlers-Danlos syndrome Type III and Ehlers-Danlos syndrome hypermobility type): Clinical description and natural history.
The hypermobile type of Ehlers-Danlos syndrome (hEDS) is likely the most common hereditary disorder of connective tissue. It has been described largely in those with musculoskeletal complaints including joint hypermobility, joint subluxations/dislocations, as well as skin and soft tissue manifestations. Many patients report activity-related pain and some go on to have daily pain. ⋯ Current medical literature further complicates differentiation and describes multiple associated symptoms and disorders. The current EDS nosology combines these two entities into the hypermobile type of EDS. Herein, we review and summarize the literature as a better clinical description of this type of connective tissue disorder. © 2017 Wiley Periodicals, Inc.
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Am J Med Genet C Semin Med Genet · Mar 2015
ReviewConnective tissue, Ehlers-Danlos syndrome(s), and head and cervical pain.
Ehlers-Danlos syndrome (EDS) is an umbrella term for a growing group of hereditary disorders of the connective tissue mainly manifesting with generalized joint hypermobility, skin hyperextensibility, and vascular and internal organ fragility. In contrast with other well known heritable connective tissue disorders with severe cardiovascular involvement (e.g., Marfan syndrome), most EDS patients share a nearly normal life span, but are severely limited by disabling features, such as pain, fatigue and headache. In this work, pertinent literature is reviewed with focus on prevalence, features and possible pathogenic mechanisms of headache in EDSs. ⋯ Particular attention is posed on a presumed subclinical cervical spine dysfunction. Standard treatment is always symptomatic and usually unsuccessful. Assessment and management procedures are discussed in order to put some basis for ameliorating the actual patients' needs and nurturing future research.
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Am J Med Genet C Semin Med Genet · Aug 2013
ReviewEbstein anomaly associated with left ventricular noncompaction: an autosomal dominant condition that can be caused by mutations in MYH7.
Left ventricular noncompaction (LVNC) is a relatively common genetic cardiomyopathy, characterized by prominent trabeculations with deep intertrabecular recesses in mainly the left ventricle. Although LVNC often occurs in an isolated entity, it may also be present in various types of congenital heart disease (CHD). ⋯ Recent studies identified mutations in the MYH7 gene, encoding the sarcomeric β-myosin heavy chain protein, in patients harboring this specific phenotype. Here, we will review the association between Ebstein anomaly, LVNC and mutations in MYH7, which seems to represent a subtype of Ebstein anomaly with autosomal dominant inheritance and variable penetrance.
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Am J Med Genet C Semin Med Genet · May 2009
ReviewNon-identical monozygotic twins, intermediate twin types, zygosity testing, and the non-random nature of monozygotic twinning: a review.
Monozygotic twins (MZ) are rarely absolutely "identical." This review discusses the types of genetic/epigenetic and prenatal environmental post-zygotic mechanisms that cause discordance within such twin pairs. Some of these mechanisms--ranging from heterokaryotypia to skewed X-chromosome inactivation--may cause extreme discordance, but these extremes are merely the more emphatic examples of discordance that, to some degree, underlies the majority of MZ twin pairs. Because of the entrenched misconception that MZ twins are necessarily identical, many MZ twin pairs are mistakenly designated as dizygotic (DZ). ⋯ However, familial monozygotic twinning is more common than suggested by the literature. Seven new families are presented in an accompanying paper. Despite the difficulties and dangers of twin pregnancy (especially so for MC twins), human twinning persists, and continues to both challenge and fascinate parents, clinicians and geneticists.