inborn errors of metabolism Flashcards
name 2 inherited metabolic disorders that make up gerrods tetrad?
alkaptonuria
cytinuria
albinism
pentosuria
describe how cystinuria may lead to renal complications?
autosomal recessive disorder that leads to defective cysteine and dibasic AA transport through epithelial cells of renal tubule –> cysteine has low solubility –> may form calculi in renal tract –> causes pain and difficulty in passing urine
what are the 4 main mechanisms of inheritance?
autosomal dominant
autosomal recessive
x-linked
mitochondrial
explain why x-linked mutations may be more serious in males?
females have 2 and males only have 1, therefore they’re more likely to express affected gene
tyrosinaemia type 2 is a possible metabolic cause for acute liver disease in neonates.
What enzyme is affected and why may this be a problem?
how may a baby present it?
fumarylacetoacetase (FAH)
when FAH is missing/doesnt work the body cant break down AA tryosine from diet and succinylacetone is made instead and builds up in blood, this substance is harmful as it can cause liver damage.
baby may show non-specific symptoms of inherited metabolis disorder e.g. vomiting, diarrhoea and poor weight gain, may present with cabbage smelling skin
OTC (ornithine transcarbamylase deficiency) is the most common urea cycle disorder in humans. What is its mechanism of inheritance?
x-linked
how is the urea cycle affected in this disorder and what are the consequences?
defective enzyme is orthinine transcarbamylase, its the final enzyme at the end of the urea cycle –> responsible for coverting carbamoyl phosphate and ornithine into citrilline –> in affected people ammonia conc increases –> lethargy and ataxia –> can result in death if treatment not given rapidly
what are the possible metabolic disorders a neonate could have if they presented with unexplained hypoglycaemia, and what may be suggested as investigations?
organic acid disorder –> organic acids
AA disorder –> AA
glycogen storage disorder –> free fatty acids
