Newborn screening for sickle cell and other hemoglobinopathies: a Canadian pilot study.
We estimated incidence of HbS disease in Quebec. It is approximately 9 cases per 100,000 births (equivalent to the incidence of the hyperphenylalanemias). Accordingly, we performed a voluntary pilot study in 9 self-identified ethnic groups; 3528 families were counselled about the relevance of newborn screening for hemoglobinopathies; and 2779 cord blood samples were collected (participation rate, 78.7%) and analyzed for Hemoglobin S and other hemoglobin variants by cellulose acetate electrophoresis. There were 95 (3.42%) positive tests on the initial (cord blood) samples, of which only 40 could be confirmed because of low participation in follow-up. We identified 8 false-positive tests; 7 had been classified initially as alpha-thalassemia trait and one as HbC heterozygosity on the first test. The relative frequency of hemoglobinopathy genes (confirmed) was: 52.5% HbS; 22.5% alpha-thalassemia; 22.5% other mutation; all but one patient with sickle cell disease were heterozygotes; the majority (71%) of HbS genes were accounted for by the 7% of screened newborns who were Black; a further 24% of the HbS genes were accounted for by 7% with Central American ancestry. Record linkage of the findings in heterozygotes for use later in life is an unsolved problem. Seventy five first-degree relatives of the 48 probands were screened in follow-up studies (64% of parents participated); 5 couples at risk for having a future child with a hemoglobinopathy were identified. Attitudes toward follow-up varied among the ethnic groups. The single family with an affected newborn (sickle cell anemia) was counselled effectively; the infant received penicillin prophylaxis.(ABSTRACT TRUNCATED AT 250 WORDS)
Yorke
D
D
DeBelle Laboratory for Biochemical Genetics (Division of Medical Genetics), Montreal Children's Hospital, Quebec.
Mitchell
J
J
Clow
C
C
Nuguid
E
E
Cadogan
R
R
Sinclair
D
D
Luscombe
S
S
Rozen
R
R
Meredith
P
P
Esseltine
D
D
D000755:Anemia, Sickle Cell / Q000175:diagnosis* / Q000453:epidemiology; D002170:Canada; D004588:Electrophoresis, Cellulose Acetate; D005006:Ethnicity; D005189:False Positive Reactions; D005312:Fetal Blood / Q000737:chemistry; D006445:Hemoglobin C Disease / Q000175:diagnosis; D006451:Hemoglobin, Sickle / Q000032:analysis; D006453:Hemoglobinopathies / Q000175:diagnosis* / Q000453:epidemiology; D006455:Hemoglobins, Abnormal / Q000032:analysis; D006801:Humans; D007231:Infant, Newborn; D015997:Neonatal Screening; D013789:Thalassemia / Q000175:diagnosis
D006451:Hemoglobin, Sickle; D006455:Hemoglobins, Abnormal