Ventricular Noncompaction and Absent Thumbs in a Newborn With Tetrasomy 5q35.2-5q35.3: An Association With Hunter-McAlpine Syndrome?
ABSTRACT We report on an infant with tetrasomy of 5q35.2-5q35.3, an interstitial triplication on one chromosome and normal complement on the other. The patient has some features of Hunter-McAlpine syndrome including intrauterine growth retardation (IUGR), almond-shaped eyes, epicanthal folds, and downturned mouth with thin vermillion of the upper lip. In addition, left ventricular noncompaction and absent thumbs were identified, which have never been described in Hunter-McAlpine syndrome. This chromosome abnormality is distinct from those previously reported. Within this region of tetrasomy is MSX2, a highly conserved homeobox containing gene. Increased copies of MSX2 have been previously associated with craniosynostosis. Our patient's only skeletal defect is absent thumbs, also potentially related to increased dosage of MSX2 which is important for limb formation. In addition, MSX2 is expressed in the developing heart and overexpression of this gene may disrupt the co-regulation of other cardiac genes in this region, namely CSX1.
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ABSTRACT: Microduplications of the Sotos syndrome region containing NSD1 on 5q35 have recently been proposed to cause a syndrome of microcephaly, short stature and developmental delay. To further characterize this emerging syndrome, we report the clinical details of 12 individuals from 8 families found to have interstitial duplications involving NSD1, ranging in size from 370 kb to 3.7 Mb. All individuals are microcephalic, and height and childhood weight range from below average to severely restricted. Mild-to-moderate learning disabilities and/or developmental delay are present in all individuals, including carrier family members of probands; dysmorphic features and digital anomalies are present in a majority. Craniosynostosis is present in the individual with the largest duplication, though the duplication does not include MSX2, mutations of which can cause craniosynostosis, on 5q35.2. A comparison of the smallest duplication in our cohort that includes the entire NSD1 gene to the individual with the largest duplication that only partially overlaps NSD1 suggests that whole-gene duplication of NSD1 in and of itself may be sufficient to cause the abnormal growth parameters seen in these patients. NSD1 duplications may therefore be added to a growing list of copy number variations for which deletion and duplication of specific genes have contrasting effects on body development.Molecular syndromology 01/2013; 3(6):247-254. DOI:10.1159/000345578
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ABSTRACT: Left ventricular non-compaction, the most recently classified form of cardiomyopathy, is characterised by abnormal trabeculations in the left ventricle, most frequently at the apex. It can be associated with left ventricular dilation or hypertrophy, systolic or diastolic dysfunction, or both, or various forms of congenital heart disease. Affected individuals are at risk of left or right ventricular failure, or both. Heart failure symptoms can be induced by exercise or be persistent at rest, but many patients are asymptomatic. Patients on chronic treatment for compensated heart failure sometimes present acutely with decompensated heart failure. Other life-threatening risks of left ventricular non-compaction are ventricular arrhythmias or complete atrioventricular block, presenting clinically as syncope, and sudden death. Genetic inheritance arises in at least 30-50% of patients, and several genes that cause left ventricular non-compaction have been identified. These genes seem generally to encode sarcomeric (contractile apparatus) or cytoskeletal proteins, although, in the case of left ventricular non-compaction with congenital heart disease, disturbance of the NOTCH signalling pathway seems part of a final common pathway for this form of the disease. Disrupted mitochondrial function and metabolic abnormalities have a causal role too. Treatments focus on improvement of cardiac efficiency and reduction of mechanical stress in patients with systolic dysfunction. Further, treatment of arrhythmia and implantation of an automatic implantable cardioverter-defibrillator for prevention of sudden death are mainstays of therapy when deemed necessary and appropriate. Patients with left ventricular non-compaction and congenital heart disease often need surgical or catheter-based interventions. Despite progress in diagnosis and treatment in the past 10 years, understanding of the disorder and outcomes need to be improved. Copyright © 2015 Elsevier Ltd. All rights reserved.The Lancet 04/2015; DOI:10.1016/S0140-6736(14)61282-4 · 39.21 Impact Factor
International Journal of Cardiology 12/2014; 177(2):639-40. DOI:10.1016/j.ijcard.2014.09.183 · 6.18 Impact Factor