Browsing by Author "Hanchard, Neil"

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    Biallelic variants in COX4I1 associated with a novel phenotype resembling Leigh syndrome with developmental regression, intellectual disability, and seizures
    (Wiley, 2019-10) Pillai, Nishitha R.; AlDhaheri, Noura S.; Gosh, Rajashri; Lim, Jaehyung; Streff, Haley; Nayak, Anuranjita; Graham, Brett H.; Hanchard, Neil; Elsea, Sarah H.; Scaglia, Fernando; Medical and Molecular Genetics, School of Medicine
    Autosomal recessive COX4I1 deficiency has been previously reported in a single individual with a homozygous pathogenic variant in COX4I1, who presented with short stature, poor weight gain, dysmorphic features, and features of Fanconi anemia. COX4I1 encodes subunit 4, isoform 1 of cytochrome c oxidase. Cytochrome c oxidase is a respiratory chain enzyme that plays an important role in mitochondrial electron transport and reduces molecular oxygen to water leading to the formation of ATP. Defective production of cytochrome c oxidase leads to a variable phenotypic spectrum ranging from isolated myopathy to Leigh syndrome. Here, we describe two siblings, born to consanguineous parents, who presented with encephalopathy, developmental regression, hypotonia, pathognomonic brain imaging findings resembling Leigh‐syndrome, and a novel homozygous variant on COX4I1, expanding the known clinical phenotype associated with pathogenic variants in COX4I1.
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    Phenotypic expansion in DDX3X - a common cause of intellectual disability in females
    (Wiley, 2018-09-15) Wang, Xia; Posey, Jennifer E.; Rosenfeld, Jill A.; Bacino, Carlos A.; Scaglia, Fernando; Immken, LaDonna; Harris, Jill M.; Hickey, Scott E.; Mosher, Theresa M.; Slavotinek, Anne; Zhang, Jing; Beuten, Joke; Leduc, Magalie S.; He, Weimin; Vetrini, Francesco; Walkiewicz, Magdalena A.; Bi, Weimin; Xiao, Rui; Liu, Pengfei; Shao, Yunru; Gezdirici, Alper; Gulec, Elif Y.; Jiang, Yunyun; Darilek, Sandra A.; Hansen, Adam W.; Khayat, Michael M.; Pehlivan, Davut; Piard, Juliette; Muzny, Donna M.; Hanchard, Neil; Belmont, John W.; Van Maldergem, Lionel; Gibbs, Richard A.; Eldomery, Mohammad K.; Akdemir, Zeynep C.; Adesina, Adekunle M.; Chen, Shan; Lee, Yi-Chien; Lee, Brendan; Lupski, James R.; Eng, Christine M.; Xia, Fan; Yang, Yaping; Graham, Brett H.; Moretti, Paolo; Medical and Molecular Genetics, School of Medicine
    De novo variants in DDX3X account for 1-3% of unexplained intellectual disability (ID) cases and are amongst the most common causes of ID especially in females. Forty-seven patients (44 females, 3 males) have been described. We identified 31 additional individuals carrying 29 unique DDX3X variants, including 30 postnatal individuals with complex clinical presentations of developmental delay or ID, and one fetus with abnormal ultrasound findings. Rare or novel phenotypes observed include respiratory problems, congenital heart disease, skeletal muscle mitochondrial DNA depletion, and late-onset neurologic decline. Our findings expand the spectrum of DNA variants and phenotypes associated with DDX3X disorders.