Galactosaemia in a Brazilian population: high incidence and cost-benefit analysis.
OBJECTIVE
To study the incidence of galactosaemia in the state of São Paulo and the benefit/cost (B/C) ratio of the introduction of neonatal screening for galactosaemia, comparing it with a selective approach.


METHODS
An enzymatic-colorimetric assay was used for the screening of total galactose (TG) in a sample of 10% of the births in São Paulo in one year and positive cases were confirmed by the activity of galactose-1-phosphate uridyltransferase (GALT). Detected and referred cases were genotyped using enzyme restriction studies for Q188R, N314D and S135L mutations of the GALT gene. The economic analysis was determined by calculating the B/C ratio and by analysis of sensitivity as a function of the incidence of the disease detected and the variation of the interest rate in the economy.


RESULTS
59 953 newborns were screened for TG, with 3 cases of galactosaemia being identified (0.26% false positives), corresponding to a frequency of 1:19 984 liveborns (95% confidence interval: 1:7494 to 1:59 953). One classical case and one Duarte 2 variant referred to as a selective approach were confirmed. With an incidence of 1:19 984, the B/C ratio was 1.04 for the 11.75% interest rate in effect in Brazil, with values already decapitalized. With a maximum possible incidence of 1:7494, the B/C ratio was 2.79.


CONCLUSIONS
There is an economic advantage in introducing neonatal screening for galactosaemia in the national neonatal screening programme. This advantage could increase with a reduction of the current interest rates in the economy.
Department of Pediatrics, School of Medicine of Ribeirão Preto, University of São Paulo, Bandeirantes Avenue, 3900, Clinics Hospital, Monte Alegre Campus, Ribeirão Preto, São Paulo, Brazil. jscamelo@fmrp.usp.br
J S
JS
Camelo
M I Machado
MI
Fernandes
L M Zanini
LM
Maciel
C A
CA
Scrideli
J L Ferreira
JL
Santos
A S
AS
Camargo
C Souza
CS
Passador
P Carvalho
PC
Leite
D Ruffato
DR
Resende
L Oliveira
LO
de Souza
R
R
Giugliani
S Moysés
SM
Jorge
D001774:Blood Chemical Analysis / Q000191:economics; D001938:Brazil / Q000453:epidemiology; D003124:Colorimetry / Q000191:economics; D003362:Cost-Benefit Analysis; D004252:DNA Mutational Analysis / Q000191:economics; D005260:Female; D005690:Galactose / Q000097:blood; D005693:Galactosemias / Q000175:diagnosis / Q000191:economics* / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening / Q000191:economics*; D006599:UDPglucose-Hexose-1-Phosphate Uridylyltransferase / Q000097:blood / Q000235:genetics
D006599:UDPglucose-Hexose-1-Phosphate Uridylyltransferase; D005690:Galactose