Versão HTML básica
342
Ferreira TD, Freire AS, Silveira-Lacerda EP, García-Zapata MT
Rev Bras Hematol Hemoter. 2012;34(5):339-44
Moreover, Giordano
(27)
affirms that the key elements to
prevent hemoglobinopathies are information, carrier diagnosis
and genetic counseling. He makes it clear that it is necessary
to investigate the family of carriers in an attempt to find other
members with the gene and to allow those with the disease a free
and well-informed reproductive choice.
The effectiveness of genetic guidance depends on accurate
diagnosis since it is not possible to base the procedure on
hypotheses. In this study, confirmation of the patients’ diagnosis
was indispensable, since different patterns were found in the
hemoglobin electrophoresis of ten patients. Previous laboratory tests
had not detected the presence of hemoglobin H or the increase in
fetal hemoglobin, findings characteristic of thalassemia. Moreover,
the two patients with clinical symptoms of disease but without the
corresponding laboratory abnormalities should be carefully evaluated
to see if in fact they have other hemoglobin alterations that were not
detected by the techniques used here, if another hematologic disorder
may be involved or if there really are clinical manifestations, even if
they are manifestations of sickle cell trait.
The laboratory screening of family members also brought
positive results. More than 70% of these individuals were
identified as having hemoglobin changes and all were informed
about their laboratory diagnosis and instructed to seek clinical
follow-up and genetic counseling.
The identification of a large number of asymptomatic
carriers underlines the preventive importance of laboratory
screening because each heterozygous carrier has a 50% chance of
passing the altered gene on to each child that he or she may have.
Indeed, the identification of four family members (2.6%) who had
diseases but had no clinical manifestations was fundamental in
advising them of the need of quick clinical care.
Few studies on family screening were found in Brazil.
A work of Bandeira et al.
(1)
, that screened family members of
patients with hemoglobin S at a referral center in Pernambuco,
is worth mentioning. These researchers found only 26.1% of
heterozygotes for sickle cell disease.
Even with the few family screening studies in Brazil, most
health policies for hemoglobinopathies direct their educational
measures toward potential parents of sickle cell children in order
to identify them and then advise them about genetic risk.
The effectiveness of these diagnostic and guidance
programs is not unique to Brazil. In Italy and the Netherlands,
for example, prevention programs have opted family screening
and counseling for patients and family members
(28)
. Fucharoen
(29)
reports that prevention programs for hemoglobinopathies in Asia
need adequate educational support and investigations need to be
expanded to the patient’s family in order for individuals to make
informed reproductive decisions. In Africa, Fattoum
(30)
says that
even with the difficulties in finding sufficient epidemiological data
for hemoglobinopathies, prevention is possible by means of a solid
program that provides information and population screening.
Overall, genetic guidance and laboratory screening of the
family turned out to be effective educational and preventive measures
as the majority of patients improved their level of knowledge and a
large number of family members who were carriers of hemoglobin
changes were identified. Such measures can reduce the morbidity and
mortality due to the disease, improve patients’ quality of life, prevent
complications and sequelae, detect changes in hemoglobin, refer
patients for genetic counseling and help with reproductive decisions.
Since the HC-UFG does not offer a specific registry for patients
with hemoglobinopathies, there was difficulty in recruiting patients;
the methodology would have been better if the sample were larger
and stratified. Different medical conduct with appropriate prophylaxis
should be adopted by the hospital team for patients with different
diagnoses. Further guidance sessions, preferably performed by a larger
number of qualified professionals, should be offered to individualswho
were unable to retain the instructions provided and the practice should
be extended to family members. More specific tests, preferably based
on molecular biology, are needed to establish a definitive diagnosis of
thalassemias and identify other anomalous hemoglobins.
References
1. Bandeira FM, Santos MN, Bezerra MA, Gomes YM, Araujo AS, Braga
MC, et al. Triagem familiar para o gene HBB*S e detecção de novos casos
de traço falciforme em Pernambuco. Rev Saude Publica. 2008;42(2):234-
41. [Article in Portuguese].
2. Simões BP, Pieroni F, Barros GM, Machado CL, Cançado RD, Salvino
MA, et al. Consenso brasileiro em transplante de células-tronco
hematopoéticas: Comitê de hemoglobinopatias. Rev Bras Hematol
Hemoter. 2010;32( Supp1):46-53.
3. Souza RA, Pratesi R, Fonseca SF. Programa de Triagem Neonatal para
Hemoglobinopatias em Dourados, MS – uma análise. Rev Bras Hematol
Hemoter. 2010;32(2):126-30.
4. Cançado RD, Jesus JA. A doença falciforme no Brasil. Rev Bras Hematol
Hemoter. 2007;29(3):203-6.
5. Naoum PC, Naoum FA. Doença das células falciformes
.
1rd ed. São
Paulo: Sarvier; 2004. 224p.
6. Moraes KC, Galioti JB. A doença falciforme: um estudo genético-
populacional a partir de doadores de sangue em São José dos Campos,
São Paulo, Brasil. Rev Bras Hematol Hemoter. 2010;32(4):286-90.
7. Guedes C, Diniz D. Um caso de discriminação genética: o traço
falciforme no Brasil. Rev Saude Coletiva. 2007;17(3):501-20.
8. Brasil. Ministério da saúde. Manual de informação e orientação genética em
herança falciforme. Brasília: Editora do Ministério da Saúde, 2010. 32p.
9. Viana-Baracioli LM, Bonini-Domingos CR, Pagliusi RA, Naoum PC.
Prevenção de hemoglobinopatias a partir do estudo em gestantes. Rev
Bras Hematol Hemoter. 2001;23(1):31-39.
10. Brasil. Ministério da saúde. Portaria n° 822, de 06 de junho de 2001.
Institui o Programa Nacional de Triagem Neonatal/PNTN [Internet].
Brasília (DF): 2001 Jun 06. [cited 2012 March 10] Available from:
http://www.saude.mg.gov.br/atos_normativos/legislacao-sanitaria/
estabelecimentos-de-saude/neonatologia/PORTARIA_822.pdf
11. Ramalho AS, Magna LA, Silva RB. A Portaria MS n.º 822/01 e a
triagem neonatal das hemoglobinopatias. Rev Bras Hematol Hemoter.
2002;24(4):244-50.
12. Brasil. Ministério da saúde. manual de normas técnicas e rotinas
operacionais do programa nacional de triagem neonatal. [internet].
Brasília (DF): Editora do Ministério da Saúde, 2002. 91p. [cited 2012
August 23]. Available from: http://dtr2001.saude.gov.br/sas/dsra/
MANUAL%202002%200456%20Neo%20Natal-%2006.JUN02.pdf
13. Brasil. Ministério da saúde. Portaria n° 1391, de 16 de agosto de 2005.
Institui as diretrizes para a Política Nacional de Atenção Integral às
Pessoas com Doença Falciforme e outras Hemoglobinopatias. [Internet].
Brasília (DF): 2005 August 16. [cited 2012 March 10] Available from:
http://www.saude.mg.gov.br/atos_normativos/legislacao-sanitaria/
estabelecimentos-de-saude/hemoterapia/por_1391.pdf