American journal of medical genetics. Part A
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Am. J. Med. Genet. A · Jan 2017
Case ReportsA novel IGF2/H19 domain triplication in the 11p15.5 imprinting region causing either Beckwith-Wiedemann or Silver-Russell syndrome in a single family.
Defects of 11p15.5 imprinting result in two growth disorders with opposite phenotypes: Beckwith-Wiedemann syndrome (BWS) characterized by overgrowth and Silver-Russell syndrome (SRS) associated with growth retardation. In a small group of patients with BWS and SRS, copy number variations (CNVs) involving the 11p15.5 region are observed; and their effects depend on the localization, size, and the parental mode of transmission. ⋯ To the best of our knowledge, this is the first report of IGF2/H19 domain triplication associated with BWS or SRS and the second report of an additional copy of this region in an individual with clinical features of SRS. This study shows that paternal IGF2/H19 domain triplication results in BWS, gives additional support to the hypothesis that the maternal amplification of IGF2/H19 domain may lead to the manifestation of SRS and underlines difficulties of genetic counseling in patients with CNVs involving the 11p15.5 region. © 2016 Wiley Periodicals, Inc.
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Am. J. Med. Genet. A · Sep 2016
Case ReportsHomozygosity for moyamoya disease risk allele leads to moyamoya disease with extracranial systemic and pulmonary vasculopathy.
Moyamoya disease is characterized by diffuse distal intracranial stenosis. Recently, RNF213 has been identified as a susceptibility gene in the development of this condition. Pulmonary hypertension is a rare progressive vasculopathy with an unknown etiology. ⋯ Interestingly, when present in a heterozygous state, this mutation causes a classic cerebral vascular disease, Moyamoya disease. In the homozygous state, the exact same mutation led to Moyamoya disease with extracranial systemic vasculopathy in at least two patients. From a clinical standpoint, cerebrovascular or pulmonary vascular investigations may be warranted in patients with pulmonary hypertension or Moyamoya disease, respectively. © 2016 Wiley Periodicals, Inc.
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Am. J. Med. Genet. A · Aug 2016
Case ReportsA new family with an SLC9A6 mutation expanding the phenotypic spectrum of Christianson syndrome.
Using targeted next generation sequencing, we have identified a splicing mutation (c.526-9_526-5del) in the SLC9A6 gene in a 9-year-old boy with mild intellectual disability (ID), microcephaly, and social interaction disabilities. This intronic microdeletion leads to the skipping of exon 3 and to an in-frame deletion of 26 amino acids in the TM4 domain. It segregates with cognitive impairment or learning difficulties in other members of the family. ⋯ Detailed neuropsychological, speech, and occupational therapy investigations in the female carriers revealed impaired oral and written language acquisition, with dissociation between verbal and performance IQ. An abnormal phenotype, ranging from learning disability with predominant speech difficulties to mild intellectual deficiency, has been described previously in a large proportion of female carriers. Besides broadening the clinical spectrum of SLC9A6 gene mutations, we present an example of a monogenic origin of mild learning disability. © 2016 Wiley Periodicals, Inc.
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Am. J. Med. Genet. A · Aug 2016
Case ReportsPregnancy after aortic root replacement in Loeys-Dietz syndrome: High risk of aortic dissection.
Loeys-Dietz syndrome due to mutations in TGFBR1 and 2 is associated with early and aggressive aortic aneurysm and branch vessel disease. There are reports of uncomplicated pregnancy in this condition, but there is an increased risk of aortic dissection and uterine rupture. Women with underlying aortic root aneurysm are cautioned about the risk of pregnancy-related aortic dissection. ⋯ Despite the normal aortic imaging and careful observation, two of the three women suffered acute aortic dissection in the postpartum period. These cases highlight the high risk of pregnancy following aortic root replacement in Loeys-Dietz syndrome. Women with this disorder are recommended to be counseled accordingly. © 2016 Wiley Periodicals, Inc.