Genetics/Metabolism Flashcards
Describe Mitchell-Riley syndrome and key tenet of growth optimization
(December 2021)
An autosomal recessive disorder with mutation of RFX6 gene on chromosome 6q22. Characterized by IUGR, neonatal diabetes, duodenal atresia, pancreatic insufficiency, anemia, hepatic siderosis, and biliary atresias. They need to be optimized for liver transplantation which includes prolonged use of PN, MCTs instead of VLCFAs, +/- low-volume enteral feedings +/- pancreatic enzyme replacement
Ornithine transcarbamylase (OTC) deficiency:
-Inheritance pattern?
-clinical & lab presentation?
-acute management of the hyperammonemia?
(October 2021)
-X-linked vs other UCDs which are AR
-affected male infants are usually well and develop vomiting, poor feeding, lethargy, hyperventilation +/- hypothermia within 2-3 DOL. Labs show respiratory alkalosis and hyperammonemia (>280 often 700-1500)
-Stop all protein, promote anabolism, stop catabolism and promote nitrogen excretion. So, (i) D10 or higher at 1-1.5x mIVF for GIR of 7-8. (ii) sodium phenyl acetate and sodium benzoate are started for nitrogen excretion also L-arginine. Hemofiltration if initial level >700 or doesn’t drop rapidly with nitrogen scavengers
CHARGE syndrome
-Findings
-genetic cause
(January 2022)
-coloboma
heart defects
atresia choanae
restriction of growth
GU anomalies
Ear anomalies
-caused by mutation in the CHD7 gene responsible for making a protein that regulates chromatin remodeling
Ellis-van Crevald syndrome
-clinical findings
-genetic cause
(January 2022)
-narrow thorax, pre or post axial polydactyly,
metacarpal/phalangeal fusion, progressive shortening of the extremities, gingival frenula, CHD, hypo plastic nails, dental anomalies
-EVC and EVC2 mutations on chromosome 4
Zellweger syndrome
-genetic mutation
-biochemical tests (3)
-what does the peroxisome do
-Rhizomelic chondrodysplasia punctata (RCDP)
(January 2022)
-PEX genes on chromosome 7
-VLCFs (normal in RCDP), plasmalogens (high in RCDP), and phytanic acid (high in RCDP)
-present in the cytoplasm of the cell and contain catalase and reducing enzymes involved in the metabolism of fatty acids and production of plasmalogens and bile acids
-rhizomelia, bony stippling, cataracts, and facies
-What syndrome is associated with a pathogenic variant of PTPN11?
-prenatal features of this syndrome?
(January 2022)
-Noonan syndrome
-increased NT, distended jugular lymphatic sacs, cystic hygroma, hydrops fetalis, pleural effusions, poly, CHD, and renal abnormalities
