Molecular genetic confirmatory testing from newborn screening samples for the common African-American, Asian Indian, Southeast Asian, and Chinese beta-thalassemia mutations.
beta-Thalassemia is a serious health problem in the United States, especially in California, due to increased Asian immigration. Neonatal screening by using high-performance liquid chromatography (HPLC) or isoelectric focusing (IEF) may lead to confusion due to interactions of various hemoglobinopathies with beta-thalassemia. Our purpose was to develop single-tube multiplexed PCR assays using original neonatal screening specimens to identify the mutations responsible for beta-thalassemia in order to expedite diagnostic confirmation. Primers were designed for two to six common ethnic-specific mutations using the amplification refractory mutation system (ARMS). This multiplex ARMS approach was standardized using DNA samples with known mutations for beta-thalassemia in those of Asian (Southeast Asian, Chinese, and Asian Indian) and African-American descent. Specimens from African-American neonates were tested for two mutations (-88 and -29); Asian Indians for five mutations (IVSI-1, IVSI-5, codons (Cd) 41/42, Cd 8/9, and 619-bp deletion); Chinese, Taiwanese, and Southeast Asians for seven mutations (Cd 41/42, Cd 17, -28, IVSII-654, Cd 71/72, IVSI-5, and IVSI-1). We identified each of these beta-thalassemia mutations in multiplexed ARMS from positive control samples. We tested 25 anonymized dried blood specimens from neonates who had been diagnosed with beta-thalassemia and who also belonged to these ethnic groups. We detected a mutation specific to the neonate's ethnic group using the ARMS approach in nearly all specimens, and the results were confirmed by sequencing. Multiplexed ARMS for ethnic-specific beta-thalassemia mutations from the original newborn screening dried blood specimens is a rapid and efficient approach for diagnostic confirmation.
Bhardwaj
Urvashi
U
Department of Pediatrics, David Geffen School of Medicine at UCLA and Mattel Children's Hospital at UCLA, Los Angeles, California 90095-1752, USA.
Zhang
Yao-Hua
YH
Lorey
Fred
F
McCabe
Linda L
LL
McCabe
Edward R B
ER
D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D044383:Black People / Q000235:genetics*; D002140:California / Q000453:epidemiology; D002681:China; D017931:DNA Primers; D005820:Genetic Testing; D006801:Humans; D007194:India; D007231:Infant, Newborn; D015997:Neonatal Screening; D016133:Polymerase Chain Reaction; D044465:White People / Q000235:genetics*; D017086:beta-Thalassemia / Q000453:epidemiology / Q000235:genetics*; D001741:Black or African American
D017931:DNA Primers