Browsing by Author "Sousa, A.B."
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- Classification of the dup 15q13.3 CNV: A National data collectionPublication . Sousa, A.; Serafim, S.; Santos, R.; Custódio, S.; Ávila, M.; Dupont, J.; Dias P, P.; Moldovan, O.; Melo, J.; Ferreira, S.; Pires, L.; Leão, M.; Sá, S.; Prior, C.; Alves, C.; Barreta, A.; Tarelho, A.; Marques, B.; Pedro, S.; Lopes, F.; Maciel, P.; Correia, H.; Dória, S.; Rendeiro, P.; Castedo, S.; Carreira, I.; Sousa, A.B.Introduction: The proximal region 15q11q14 is one of the most unstable regions in the human genome, with six recognizable break points (BP1-BP6). In 15q13.3 there is a recurrent small CNV (BP4-BP5) consisting of a 350-680 Kb duplication, encompassing the CHRNA7 gene, which encodes the alpha 7 subunit of the neuronal nicotinic acetylcholine receptor. Although microdeletions of CHRNA7 are known to cause intellectual disability and neuropsychiatric phenotypes with high penetrance, the patogenicity of CHRNA7 duplications remains unclear. Microduplication 15q13.3 seems to be associated with a phenotypic spectrum of cognitive impairment and neuropsychiatric/neurobehavioral disorders. However, the penetrance of this CNV is considered incomplete since it is present in clinically unaffected individuals in the general population and it is frequently inherited from apparently clinically normal parents. Nonetheless, some pedigree studies have found a history of neuropsychiatric problems among carrier family members. This study aimed at re-evaluating the dup 15q13.3 CNV in national laboratories. Materials and Methods: Our study collected data on 15q13.3 microduplications in eight Portuguese genetics laboratories, among subjects referred for microarray. Results: Here we present a total of seventeen cases with dup 15q13.3. The subjects had somewhat variable phenotypes, with a bias towards developmental delay and autism spectrum disorders. Inheritance was established for eight of the subjects, and the majority originated from the father. We had no access to clinical data on carrier parents. No de novo CNV was found. All laboratories involved classified this variant as of uncertain significance. Discussion/Conclusion: To better determine whether this CNV is benign or pathogenic, careful characterization of patient and control cohorts must be performed, including detailed patient phenotyping, inheritance, clinical evaluation of carrier parents, prevalence in controls, as well as genetic functional studies. We strongly support the creation of a national database for uncertain CNVs in order to clarify the relevance of these recurrent findings, allowing a definitive classification in either pathogenic or benign.
- Dunnigan-type familial partial lipodystrophy in a large Portuguese kindredPublication . Moldovan, O.; Alves, A.C.; Medeiros, A.M.; Sousa, A.B.; Bourbon, M.INTRODUCTION : The lipodystrophies are a clinically heterogeneous group of acquired or inherited disorders affecting adipose tissue distribution. Dunnigan-type familial partial lipodystrophy (FPLD2, OMIM 151660, the most prevalent subtype) is a rare autosomal dominant disease, characterized by selective absence of adipose tissue in the extremities and trunk and accumulation of fat in the face, neck and supraclavicular fossa. The patients have a muscular hypertrophic appearance, especially in the lower limbs. Affected children are born with normal fat distribution, may present hyperlipidemia in childhood and after puberty start to progressively lose the subcutaneous fat. Later in life, affected adults may experience metabolic disorders including hypertriglyceridemia, insulin resistance, diabetes mellitus, hepatic steatosis and high blood pressure. Acanthosis nigricans, hirsutism, menstrual abnormalities and polycystic ovarian disease can also occur in affected women. The phenotype appears more pronounced in females. The aim of this study was to characterize clinically and molecularly a family with clinical diagnosis of lipodystrophy.
- Dunnigan-type familial partial lipodystrophy in a large Portuguese KindredPublication . Moldovan, O.; Alves, A.C.; Medeiros, A.M.; Sousa, A.B.; Bourbon, MafaldaThe lipodystrophies are a clinically heterogeneous group of acquired or inherited disorders affecting adipose tissue distribution. Dunnigan-type familial partial lipodystrophy (FPLD2, OMIM 151660, the most prevalent subtype) is a rare autosomal dominant disease, characterized by selective absence of adipose tissue in the extremities and trunk and accumulation of fat in the face, neck and supraclavicular fossa. The patients have a muscular hypertrophic appearance, especially in the lower limbs. Affected children are born with normal fat distribution, may present hyperlipidemia in childhood and after puberty start to progressively lose the subcutaneous fat. Later in life, affected adults may experience some metabolic disorders including hypertriglyceridemia, insulin resistance, diabetes mellitus, hepatic steatosis and high blood pressure. Acanthosis nigricans, hirsutism, menstrual abnormalities and polycystic ovarian disease can also occur in affected women. The phenotype appears more pronounced in females. The aim of this study was to characterize clinically and molecularly a family with clinical diagnosis of lipodystrophy.