We follow the
HGVS sequence variant nomenclature
and
IUPAC standards.
Context nucleotide sequence:
GTGAGGCTCC [CTCCCCTGCTCCGACCCGGGCTCC/-] TCGCCCGCCC (Strand: +)
Comments: Found in six cases. In 1st case, the IVS I-11 (-24bp) reported in compound heterozygosity the with –FIL deletion [IthaID: 311], in a 23-year-old Kadazan-Dusun individual presented with reduced level of Hb 8.8 g/dL, MCV 68.6 fL, MCH 21.3 pg and RBC 4.13 10^12/L, without hepatosplenomegaly and transfusion history. HPLC analysis shown elevated level of HbA2 6 % and HbF 3.7 %, whereas a small peak 15 at zone 11 found with CE. In 2nd case, the IVS I-11 (-24bp) reported in compound heterozygosity with IVS I-5. The individual presented with decreased level of Hb 11.7 g/dL, MCV 63.3 fL, MCH 19.1 pg and RBC 6.11 10^12/L and elevated level of HbA2 4.5 % and HbF 4.8 %. The rest 4 cases are related cases from the same family. The IVS I-11 (-24bp) found in a 29-year old Sabah/Rungus ethnicity female and her 52-year old father in compound heterozygosity with the Hb A2-Deventer [IthaID: 2573]. The daughter presented with normal level of Hb 13.6 g/dL, MCV 81.4 fL, MCH 26.6 pg, RBC 5.12 10^12/L, HbF and HbA and reduced level of HbA2 1.4%. Her father, presented with Hb 15.1 g/dL, MCV 84.6 fL, MCH 36.7 pg, RBC 4.6 10^12/L, reduced level of HbA2 and normal level of HbF and HbA. The other two cases, were also compound heterozygous with the Hb A2-Deventer, presented with Hb range 12.7-16.4 g/dL, MCV 78.6-87.4 fL, MCH 26-32.4 pg and RBC 4.76-5.06 10^12/L. HPLC and CE analysis shown normal level of HbA2 0-0.2 % and HbF 0.4-0.7 %, HbA 98-100 % respectively, in both cases. In a recent publication [PMID: 34708592], the 24bp deletion found in a 40-year-old Chinese male and his father, both presented with normal levels of the hematological and electrophoretic parameters.