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- Published on: 23 November 2020
- Published on: 10 November 2020
- Published on: 23 November 2020Wilson disease: the affected newborn
The disparity between estimates of the clinical and genetic prevalence of Wilson’s disease (WD) may be due to under-diagnosis or reduced penetrance of ATP7B mutations.
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The widely quoted disease prevalence of 1:30,000 from a 1984 paper is corroborated by a 4 recent studies giving estimates from 1:29,000 to 1:40,000 (1). By contrast the calculated frequency amongst 1000 UK control subjects of individuals predicted to carry two mutant pathogenic ATP7B alleles was 1:7026(2). Amongst 14,835 Korean neonatal dried blood spots it was 1:7561 (3).
Assuming that under-diagnosis is not responsible these data suggest that penetrance in WD is approximately 20%. Interrogating the Genome Aggregation Database (gnomAD) revealed 231 WD-associated ATP7B variants giving an initial estimated population prevalence of around 1 in 2400. Using standardised genetic variant effect prediction algorithms WD-associated ATP7B variants with predicted low penetrance were excluded giving a revised disease estimate of around 1 in 20,000 and a penetrance of 12% (4).
WD thus resembles alpha-1 antitrypsin deficiency (AAT); only ~10% PiZ individuals develop liver disease. So, what is the prognosis of the newborn found to have the same genotype as a sibling proband with AAT or WD and liver disease - the same risk as the general population or higher? In AAT, if the first PiZ child of PiZ heterozygote parents had unresolved liver disease, there was a 78% chance that a second PiZ child will h...Conflict of Interest:
None declared. - Published on: 10 November 2020The newborn with 2 WD mutations
The disparity between estimates of the clinical and genetic prevalence of Wilson’s disease (WD) may be due to under-diagnosis or reduced penetrance of ATP7B mutations.
Show More
The widely quoted disease prevalence of 1:30,000 from a 1984 paper is corroborated by 4 recent studies giving estimates from 1:29,000 to 1:40,000 (1). By contrast the calculated frequency amongst 1000 UK control subjects of individuals predicted to carry two mutant pathogenic ATP7B alleles was 1:7026(2). Amongst 14,835 Korean neonatal dried blood spots it was 1:7561 (3).
Assuming that under-diagnosis is not responsible these data suggest that penetrance in WD is approximately 20%. Interrogating the Genome Aggregation Database (gnomAD) revealed 231 WD-associated ATP7B variants giving an initial estimated population prevalence of around 1 in 2400. Using standardised genetic variant effect prediction algorithms WD-associated ATP7B variants with predicted low penetrance were excluded giving a revised disease estimate of around 1 in 20,000 and a penetrance of 12% (4).
WD thus resembles alpha-1 antitrypsin deficiency (AAT); only ~10% PiZ individuals develop liver disease. So, what is the prognosis of the newborn found to have the same genotype as a sibling proband with AAT or WD and liver disease - the same risk as the general population or higher? In AAT, if the first PiZ child of PiZ heterozygote parents had unresolved liver disease, there was a 78% chance that a second PiZ child will hav...Conflict of Interest:
None declared.