Publications by authors named "Amy Lewanda"

We describe a 10-month-old female with Diamond-Blackfan anemia (DBA) who presented with macrocytic anemia and reticulocytopenia. Whole exome sequencing revealed a intronic variant in (NM_000988.3:c.

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Article Synopsis
  • The study focuses on a protein called SPOUT1/CENP-32, which is crucial for proper chromosome alignment during cell division.
  • When this protein is depleted, it causes problems like centrosome detachment and chromosome misalignment, leading to significant developmental issues.
  • The research also links genetic variants in humans to neurodevelopmental delays and identifies a disorder called SpADMiSS, characterized by symptoms like developmental delays, microcephaly, seizures, and short stature due to defects in cell division.
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Background: Recent advances in medical care have increased life expectancy and improved the quality of life for people with Down syndrome (DS). These advances are the result of both pre-clinical and clinical research but much about DS is still poorly understood. In 2020, the NIH announced their plan to update their DS research plan and requested input from the scientific and advocacy community.

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Proper embryonic and postnatal skeletal development require coordination of myriad complex molecular mechanisms. Disruption of these processes, through genetic mutation, contributes to variation in skeletal development. We developed a high-throughput N-ethyl-N-nitrosourea (ENU)-induced saturation mutagenesis skeletal screening approach in mice to identify genes required for proper skeletal development.

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Objective: To determine the frequency of dietary supplement use for children with Down syndrome, and to obtain additional descriptive data regarding the age of initial treatment, cost, perceived benefits, and disclosure of use to the pediatrician.

Study Design: An anonymous questionnaire in English and Spanish was created for parents of children under age 18 years with Down syndrome. Surveys were completed in our clinic, or accessed on a number of Down syndrome-related websites.

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Copy number variants of the X-chromosome are a common cause of X-linked intellectual disability in males. Duplication of the Xq28 band has been known for over a decade to be the cause of the Lubs X-linked Mental Retardation Syndrome (OMIM 300620) in males and this duplication has been narrowed to a critical region containing only the genes MECP2 and IRAK1. In 2009, four families with a distal duplication of Xq28 not including MECP2 and mediated by low-copy repeats (LCRs) designated "K" and "L" were reported with intellectual disability and epilepsy.

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Down syndrome is a common chromosome disorder affecting all body systems. This creates unique physiologic concerns that can affect safety during anesthesia and surgery. Little consensus exists, however, on the best way to evaluate children with Down syndrome in preparation for surgery.

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The vertebrate basic helix-loop-helix (bHLH) transcription factor ATOH7 (Math5) is specifically expressed in the embryonic neural retina and is required for the genesis of retinal ganglion cells (RGCs) and optic nerves. In Atoh7 mutant mice, the absence of trophic factors secreted by RGCs prevents the development of the intrinsic retinal vasculature and the regression of fetal blood vessels, causing persistent hyperplasia of the primary vitreous (PHPV). We therefore screened patients with hereditary PHPV, as well as bilateral optic nerve aplasia (ONA) or hypoplasia (ONH), for mutations in ATOH7.

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Mutations of LAMB2 typically cause autosomal recessive Pierson syndrome, a disorder characterized by congenital nephrotic syndrome, ocular and neurologic abnormalities, but may occasionally be associated with milder or oligosymptomatic disease variants. LAMB2 encodes the basement membrane protein laminin beta2, which is incorporated in specific heterotrimeric laminin isoforms and has an expression pattern corresponding to the pattern of organ manifestations in Pierson syndrome. Herein we review all previously reported and several novel LAMB2 mutations in relation to the associated phenotype in patients from 39 unrelated families.

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X-linked Recessive Chondrodysplasia Punctata (CDPX1) is due to a defect in arylsulfatase E (ARSE), located on Xp22.3. Neither the substrate nor function of the encoded warfarin-sensitive arylsulfatase has been identified and molecular analysis remains the only confirmatory diagnostic test.

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We recently identified mutations of ARX in nine genotypic males with X-linked lissencephaly with abnormal genitalia (XLAG), and in several female relatives with isolated agenesis of the corpus callosum (ACC). We now report 13 novel and two recurrent mutations of ARX, and one nucleotide change of uncertain significance in 20 genotypic males from 16 families. Most had XLAG, but two had hydranencephaly and abnormal genitalia, and three males from one family had Proud syndrome or ACC with abnormal genitalia.

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