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Copyright ©The Author(s) 2015.
World J Obstet Gynecol. Nov 10, 2015; 4(4): 86-94
Published online Nov 10, 2015. doi: 10.5317/wjog.v4.i4.86
Table 1 Cross table indicating the risk for the progeny of carriers of the common β globin gene defects
β traitsβ minorHbSHbEHbCHbDHbY
β minorβ major
HbSSCDSCD
HbEβ majorSCDβ minor
HbCβ minor?SCDβ minorβ minor
HbDβ minorSCDβ minorNormalNormal
HbX??????
Table 2 Genotype/phenotype correlation, indicative MCV/MCH values, HPLC/CE separations and presence of HbH or Hb Bart's and genetic risk in alpha thalassemia
Genotypeα-thalassemiaPhenotypeMCVHPLCHbH (adult)Genetic risk for the
Condition nameMCHCEHb Bart’s (newborn)progeny of carriers
αα/ααNormalNormalNormalNormalAbsentNone
Absent
-α/ααα+ heterozygousEventually anemicborderlineNormalAbsentHbH
0%-5%
-α/-αα+ homozygousMildly anemicLowNormalAbsentHbH
HbA2↓5%-10%
--/αα1α° heterozygousMildly anemicLowNormalAbsentHbH or Hb Bart’s HF
HbA2↓5%-10%
--/-α2HbH diseaseIntermediateLowerHbH0%-10%HbH or Hb Bart’s HF
hemolytic anemiaHb Bart’s10%-30%
HbA2↓↓
--/--Hb Bart’sSevere intrauterineSevereNo HbA or HbF in newbornHb PortlandLethal to newborn.
Hydrops Fetalishemolytic anemiamorphologyHb Bart’sLife threatening for mother
Table 3 Indicative parameters usually associated with carrier states
Carrier ofHbMCVMCHRBCHbA2HbFApproximately HbS (%)Approximately HbC (%)Approximately HbE (%)Approximately HbD (%)Smear
Alpha thalL2L2L2NN1NTC, APC
Beta thalLLLN or EE4N or ETC, APC
HbSN1N1N1NN3N45-256Normal5
HbCN1N1N1NNN45-256TC
HbEL-NL-NL-NNNN or E± 25TC, APC
HbDN1N1N1NNN± 45Normal