Hb Lepore is one of the most common abnormal haemoglobins in Caucasians in Central Portugal and in the Spanish Alta Extremadura (0.28% in a survey of school children). A group of 19 Portuguese and 14 Spanish Hb Lepore carriers (all unrelated) was characterised at the molecular level by the polymerase chain reaction, sequencing and restriction enzyme analysis. The Portuguese and one Spanish carrier were heterozygous for Hb Lepore-Baltimore, whereas all other Spanish subjects were Hb Lepore-Washington-Boston carriers. Sequencing of the Hb Lepore-Baltimore gene further established the crossover at delta 68-beta 84, a region two codons (CDs) shorter than that previously described and easily confirmed by digestion with MaeI and BanI. Data from haplotype analysis suggest that this crossover occurred as an independent event on the Iberian Peninsula. The haematological data were similar in both groups except for the levels of Hb F and the G gamma chain, which were significantly higher in the Hb Lepore-Baltimore heterozygotes. Quantification of the globin chains and the mRNA transcripts showed that the delta beta gene is transcribed at a higher level than the delta gene with levels of translation giving rise to 10%-15% of Hb Lepore. The different levels of Hb F observed in the two groups are the results of the higher transcription rate of the gamma genes in Hb Lepore-Baltimore heterozygotes and an apparently less efficient translation of G gamma genes in Hb Lepore-Washington-Boston heterozygotes.

Background Diamond Blackfan anemia (DBA) is a genetically and clinically heterogeneous ribosomopathy and inherited bone marrow failure syndrome characterized by anemia, reticulocytopenia and decreased erythroid precursors in the bone marrow with an increased risk of malignancy and in approximately 50%, physical abnormalities. Methods We retrospectively analyzed clinical data from 77 patients with DBA born in the Russian Federation from 1993–2014. In 74 families there was one clinically affected individual; in only three instances a multiplex family was identified. Genomic DNA from 57 DBA patients and their first-degree relatives was sequenced for mutations in RPS19, RPS10, RPS24, RPS26, RPS7, RPS17, RPL5, RPL11, RPL35a and GATA1. Results Severe anemia presented before 8 months of age in all 77 patients; before 2 months in 61 (78.2%); before 4 months in 71 (92.2%). Corticosteroid therapy was initiated after 1 year of age in the majority of patients. Most responded initially to steroids, while 5 responses were transient. Mutations in RP genes were detected in 35 of 57 patients studied: 15 in RPS19, 6 in RPL5, 3 in RPS7, 3 each in RPS10, RPS26 and RPL11 and 1 each in RPS24 and RPL35a; 24 of which having not been previously reported. In one patient a balanced chromosomal translocation involving RPS19 was found. No mutations in GATA1 were found. Conclusion In our cohort from an ethnically diverse population the distribution of mutations among RP genes was approximately the same as was reported by others, although within genotypes most of the mutations had not been previously reported.

We analyzed blood samples from more than 200 normal adults, and quantified their Hb F by cation-exchange high-performance liquid chromatography. In several subjects with slightly elevated Hb F (0.4-4.3%), we determined the Ggamma levels in the Hb F and DNA sequence variations in the locus control region II and in the Ggamma and Agamma promoters. About 25% of the approximately 200 normal teenaged high school students had elevated Hb F; detailed analyses of some 20 students, selected at random, identified most as females with a homozygosity for the C-->T variation at position -158 (Ggamma). One 11-year-old boy was heterozygous for the A-->G change at position -161 (Ggamma); he and two of his relatives had approximately 4% Hb F, high Ggamma values, and a high level of (mainly) Ggamma-mRNA. Nearly 40 normal adults from Macedonia and from Georgia (mostly Caucasians) were tentatively identified as Swiss HPFH heterozygotes because slightly elevated Hb F levels were observed at least once. Many of these persons were heterozygous or homozygous for the C-->T mutation at -158 (Ggamma), and a few carried a gamma-globin gene triplication. The C-->T change appears to be an important factor predisposing the adult to increased Hb F production. Evidence suggests a gene dose effect in (mildly) anemic adults; however, other factors besides the C-->T change at -158 (Ggamma), including factors not linked to the beta-globin region, may cause an increase in gamma-chain synthesis.

The present study provides information about the alpha / beta and alpha 2 / alpha 1-mRNA ratios in reticulocytes of normal adults and individuals with different alpha-globin gene deficiencies; it found its origin in analytical data of blood samples from a Laotian couple and their newborn baby. The father carried the 4.2 kb deletion on one chromosome and a TAA --> CAA mutation at the terminating codon of the alpha 2 gene (Hb Constant Spring or CS) on the other chromosome. The mother had the 3.7 kb deletion on one chromosome and a TA A --> TAT mutation at the terminating codon of the alpha 2-globin gene (Hb Paksé) of the second chromosome. The baby was a compound heterozygote for the two termination codon mutations. The mRNA data for this family were compared to those for persons with several well-defined alpha-globin gene deficiencies. The results confirm the importance of the alpha 2 alpha 1-mRNA for the synthesis of alpha chains in alpha-thalassemia-2 homozygotes (-alpha/-alpha) and in patients with Hb H disease due to the deletion of three alpha-globin genes (-alpha/--). Furthermore, the MRNA production of the alpha 1-globin gene on the chromosome with the alpha CS mutation (alpha CS alpha) is only one-half of that by the alpha 2 alpha 1-globin gene of a chromosome with a 3.7 or 4.2 kb deletion, explaining the greater severity of, and higher Hb H level in Hb H patients with the alpha CS alpha condition (alpha CS alpha/--) as compared to those with the three gene deletion (-alpha/--). The methodology could be useful as a preliminary screening for the presence of point mutations leading to the functional loss of a single alpha-globin gene, provided common deletional alleles have been excluded.