A novel HLA-B*18:80 allele identified by SBT typing in an Italian bone marrow volunteer donor

A novel allele, officially named B*18:80, was detected in a Caucasoid individual by polymerase chain reaction-sequence-specific primers and SBT. The new allele differs from B*18:01:01 at two nucleotidic positions in codon 24 at exon 2.

Molecular modelling of HLA-B*35:132

Here we describe the molecular modelling of the new variant HLA-B*35:132. This allele shows one mismatch with B*35:01:01:01 in exon 3 at position 575 where a T is substituted by a C, which implies an amino acidic change from Leucine to Proline. This seems not to alter the molecular structure and not to compromise the HLA complex and T-cell receptor interaction.

Identification of two novel HLA-A alleles: A*24:199 and A*02:324

Here, we describe two new HLA-A alleles: A*24:199 and A*02:324. The two new variants are attributed to a single nucleotide mutation namely A→C for A*24:199 and G→A for A*02:324. Both point mutations are responsible for a change in translated amino acids.

Description of the new allele HLA-DQB1*04:03:02

A new variant of HLA-DQB1*04:03 allele officially designated as HLA-DQB1*04:03:02 was detected in two unrelated Caucasoid individuals by polymerase chain reaction-sequence-specific primers and SBT. The new allele nucleotide sequence differs from HLA-DQB1*04:03:01 for a single silent point mutation in exon 2 at position 159, codon 21.

Sequence of a novel HLA-B*51 allele in a volunteer haematopoietic stem cell donor

We describe a novel HLA-B*51 allele detected by DNA direct sequencing. The sequence of this allele has been officially named B*51:78 as a confirmatory sequence. This new allele nucleotide sequence differs from HLA-B*51:01:01 for two point mutations in exon 2 where codons 79-80 change from CGG-ATC to CGC-ACC (p.Ile80Thr).

A silenced allele in the Colton blood group system

BACKGROUND

The antigens of the Colton blood group system, Co(a) and Co(b), are encoded by a single gene that produces the aquaporin-1 (AQP1) protein, a water channel-forming protein, and are characterized by a single nucleotide polymorphism (SNP). A healthy Caucasoid blood donor originally typed as Co(a-b-) with commercial anti-Co(b) typed Co(a-b+) when retested with another anti-Co(b). Retyped with two different molecular biology methods, the sample came out Co(a)/Co(b). With the aim of understanding these discrepancies, serological, cytometric and molecular biology tests were carried out.

METHODS

Absorption/elution studies with propositus red cells and controls were performed. The region spanning exon 1 to exon 4 of the Colton gene was sequenced, and flow cytometry analyses were carried out.

RESULTS

Absorption/elution studies showed the absence of Co(a) and a weak expression of Co(b). DNA sequencing confirmed a CT heterozygosity at nucleotide position 134 (i.e. Co(a)/Co(b)), and an additional heterozygous CT was found at position 112. The presence of the Co(b) allele that encodes for the Co(b) antigen was confirmed. The new allele has the base cytosine at nucleotide 134 (Co(a)), in cis with the new nucleotide 112T. The nucleotide substitution 112C>T causes a missense mutation leading to an amino acid change from proline (CCG) to serine (TCG) at codon 38.

CONCLUSION

The substitution found at codon 38 results in a modified AQP1 protein which explains the Co(a-b+) phenotype and possibly the weak expression of Co(b).

Characterization of two novel HLA class I alleles: HLA-A*310103 and HLA-B*9531

Two novel human leucocyte antigen (HLA) class I alleles were characterized by means of sequencing-based typing techniques. HLA-A*310103 was identified in a cord blood unit from a Caucasoid individual. The sequence of this allele is identical to that of HLA-A*310102 except for a silent mutation in exon 3 at position 480 (G --> A). HLA-B*9531 was found in a Caucasoid female patient registered on the heart transplantation waiting list in the North Italy Transplant programme. This new variant differs from HLA-B*1503 at position 572 (G --> C) in exon 3. This nucleotide change leads to an amino acidic substitution at codon 167 from tryptophan to serine.

Identification of two novel HLA-DRB1*11 alleles (DRB1*110404 and DRB1*1161) in two Italian cord blood units

We describe the isolation and characterization of two novel HLA-DRB1*11 alleles, officially named DRB1*1161 and 110404. These two new variants were both identified in two Caucasoid individuals. The exon 2 sequence of DRB1*1161 is identical to that of DRB1*110101 except at codon 41, where a nucleotide substitution (GAC>AAC) is responsible for an amino-acidic change from Asp to Asn. The exon 2 sequence of the second novel allele described here, DRB1*110404, differs from that of DRB1*110401 only at codon 34 where the nucleotidic change CAA>CAG gives rise to a silent mutation.

Characterization of a novel HLA-DRB1*04 allele (DRB1*0460) in the Italian population

We report the identification of a novel HLA-DRB1*04, officially named DRB1*0460. It was detected during performing HLA-DRB1 high resolution typing by DNA sequencing-based method. The exon 2 nucleotide sequence of DRB1*0460 is identical to that of DRB1*040301 except at codon 63 (AGC-->AAC), changing the encoded serine to asparagine.

Distribution of killer cell immunoglobulin-like receptors genes in the Italian Caucasian population

Background

Killer cell immunoglobulin-like receptors (KIRs) are a family of inhibitory and activatory receptors that are expressed by most natural killer (NK) cells. The KIR gene family is polymorphic: genomic diversity is achieved through differences in gene content and allelic polymorphism. The number of KIR loci has been reported to vary among individuals, resulting in different KIR haplotypes. In this study we report the genotypic structure of KIRs in 217 unrelated healthy Italian individuals from 22 immunogenetics laboratories, located in the northern, central and southern regions of Italy.

Methods

Two hundred and seventeen DNA samples were studied by a low resolution PCR-SSP kit designed to identify all KIR genes.

Results

All 17 KIR genes were observed in the population with different frequencies than other Caucasian and non-Caucasian populations; framework genes KIR3DL3, KIR3DP1, KIR2DL4 and KIR3DL2 were present in all individuals. Sixty-five different profiles were found in this Italian population study. Haplotype A remains the most prevalent and genotype 1, with a frequency of 28.5%, is the most commonly observed in the Italian population.

Conclusion

The Italian Caucasian population shows polymorphism of the KIR gene family like other Caucasian and non-Caucasian populations. Although 64 genotypes have been observed, genotype 1 remains the most frequent as already observed in other populations. Such knowledge of the KIR gene distribution in populations is very useful in the study of associations with diseases and in selection of donors for haploidentical bone marrow transplantation.

Description of a new HLA-DRB1*1104, DRB1*110403

We report here the exon 2 sequence of the novel HLA-DRB1*110403 which differs from DRB1*110401 by a single synonymous nucleotide substitution at codon 78, where TAC is substituted by TAT. The variant originally identified in a Caucasoid individual was confirmed by cloning and sequencing.

HLA-A*2626, a new allele identified through external proficiency-testing exercise

A new allele, officially named HLA-A*2626, has been detected in a blood sample belonging to a Caucasian subject human leucocyte antigen typed for Lombardy Region external proficiency-testing exercise. The DNA sequences of exons 2, 3 and 4 of this new allele are identical to those of HLA-A*2601 except at codon 259 of exon 4 (CCT-->CTT). This variation modifies the encoded protein from proline to leucine.

Identification of a new HLA-B variant, HLA-B*5615

A new HLA-B allele, B*5615, has been identified in a Caucasian individual by sequence-based typing. This allele shows a sequence identical to that of HLA-B*5601 except for two nucleotide substitutions that cause a change from TTA to TAC at codon 116 and an amino acidic change from Leucine to Tyrosine in the mature protein.

Description of a new HLA-DRB1 allele, DRB1*1150

We report the identification of a novel HLA-DRB1*11 using sequence-based typing. This new allele, officially named DRB1*1150, was detected while performing HLA-DRB1 high-resolution typing of a candidate for bone marrow transplantation. DRB1*1150 is identical to DRB1*1143 except at nucleotides 200 and 227, where a T is substituted by a C and a T by an A, respectively. These differences give rise to two amino acid substitutions at codons 38 (Val-->Ala) and 47 (Phe-->Tyr).

HLA-B*1819, a novel HLA-B allele identified by sequence-based typing

In this brief communication, we describe a novel human leukocyte antigen-B (HLA-B) allele (HLA-B*1819). This allele, found in an Italian Caucasian individual, differs from HLA-B*180101 by three nucleotide changes in exon 3. These mutations are located at positions 527, 538, and 539 where a T, a C, and a T are substituted respectively, by an A, a T, and a G, leading to three aminoacidic substitutions at codon 152 from Valine to Glutamic Acid (GTG-->GAG), at codon 155 from Histidine to Glutamine (CAC-->CAG), and at codon 156 from Cysteine to Tryptophan (TGT-->TGG).

Identification of two new HLA-B alleles, HLA-B*0732 and HLA-B*5809, by sequence-based typing

Here, we have described the characterization of two novel human leukocyte antigen-B (HLA-B) alleles. The new alleles, HLA-B*0732 and HLA-B*5809, were identified in Italian Caucasian individuals. B*0732 differs from HLA-B*0708 by one nucleotidic change at position 412 (from G to A) in exon 3, leading to an amino acidic substitution from Asp (GAC) to Asn (AAC) at codon 114. The sequence of B*5809 is identical to that of HLA-B*5801, except for a point mutation at position 583 in exon 3, where a T is substituted by a C. This change leads to an amino acidic substitution from Tyr (TAC) to His (CAC) at codon 171.

HLA-B*5808, a new HLA-B allele characterized by sequence based typing

This brief communication describes a new HLA-B allele (HLA-B*5808) detected in an Italian white volunteer bone marrow donor. With serology, this subject was typed as HLA-B15,17, whereas with molecular biology B*15, B*51, B*52 and/or B*58 could be assigned. In order to clarify the results, direct and cloning sequencing of exons 2, 3 and 4 were carried out. This new allele is identical to HLA-B*5801 in exon 2 except for a silent point mutation at nucleotide 141 where a C is substituted by a T; exons 3 and 4 are typical of HLA-B*51, B*52 and B*78. The peculiar sequence of B*5808 could explain the discrepancy between the serological and molecular typing results.

Characterization of two new HLA-B alleles by sequence-based typing: HLA-B*0817 and HLA-B*1311

In this brief communication we report the characterization of two new HLA-B variants officially named HLA-B*0817 and HLA-B*1311. The HLA-B*0817 allele was identified in a Caucasoid male candidate for renal transplantation in the North Italy Transplant program. The nucleotidic sequence of exons 2, 3 and 4 of this novel allele is identical to that of HLA-B*0804 except for three point mutations in exon 2: from A to G at position 259, from C to G at position 261 and from G to A at position 302. These mutations are responsible for two aminoacidic substitutions [Asn (r) Glu, codon 63, and Ser (r) Asn, codon 77]. HLA-B*1311 was found in a volunteer donor belonging to National Marrow Donor Program(R). This new variant is identical to that of HLA-B*1301 except for three nucleotide substitutions at positions 353, 355 and 369 leading to two aminoacidic variations from Ile to Thr at codon 94 and from Ile to Leu at codon 95 and a silent mutation at codon 99.

Demographic and geographic variations of oral health among African Americans based on NHANES III

As efforts continue to improve the health of all US citizens, oral health must not be overlooked. Oral health is an integral part of overall health status and oral diseases are among the most prevalent of all health problems.

OBJECTIVES

To describe the oral health status and oral health behaviors of African Americans.

METHODS

The National Health and Nutrition Examination Survey (NHANES III) data set was used to examine a range of oral health indicators of African Americans with specific attention to demographic and geographic factors. The original data set consisted of 20,050 subjects, gathered through the use of complex, multi-stage, stratified and clustered sampling techniques. Only African Americans were included in this study which resulted in a sample of 5,616. Statistical analysis was conducted to allow the proper modeling of the complex, stratified, multistage survey design and sample weights of NHANES III.

RESULTS

Sixty-two percent of respondents indicated that they only visit the dentist when needed and had no regular visitation schedule. Dental health was worse for those individuals who were poor, unemployed, and uninsured. Regional differences in dental care appeared with individuals living in the south reporting poorer dental health.

CONCLUSIONS

The findings from this study are useful for identifying sociodemographic and geographic factors related to oral health status. The insights gained from this study illustrate the need for tailoring oral health promotion programmes and services to specific groups within the African American community because service utilisation and response patterns and perceptions may be different.

A novel HLA-DRB1 allele, DRB1*0707

We report herein the identification of a new HLA-DRB1 allele, DRB1*0707. This new allele was seen in a volunteer bone marrow donor (ID#118069) belonging to the German bone marrow donor registry (DKMS). HLA-DRB1*0707 was detected while performing HLA-DRB1 high resolution typing by sequence based typing. This novel allele differs from DRB1*070101 by a single nucleotide substitution at position 163 (C-->T) in exon 2.

Identification of a novel HLA-DRB1 allele: DRB1*1353

In this report we describe a new HLA-DRB1 allele, DRB1*1353, which was initially recognized by a discrepancy between the results obtained with polymerase chain reaction using sequence-specific oligonucleotide (PCR-SSO) and sequence-specific primers (PCR-SSP). Sequence-based typing revealed sequence differences with other known HLA-DRB1 alleles. DRB1*1353 is identical to DRB1*13011 except for two nucleotide substitutions at nucleotide 84 (C(r)G) and at nucleotide 140 (T(r)A). These differences give rise to two amino acid substitutions at codons 28 and 47 from Asp to Glu and from Phe to Tyr, respectively.

Characterization of a new HLA-DRB3 allele, DRB3*0217, by direct sequencing

We report the identification of a novel DRB3*02 using sequence-based typing (SBT). This new allele, officially named DRB3*0217, was detected while performing HLA high resolution typing of a bone marrow recipient and his siblings. DNA sequencing demonstrated the presence of a nucleotide substitution in exon 2 at position 199 where a C was substituted by a T. This point mutation at codon 67 (CTC-->TTC) has resulted in an amino acid substitution from Leucine to Phenylalanine.

Description of a new HLA-DRB1 allele, DRB1*1139

We report the identification of a novel DRB1*11 using sequence-based typing. This new allele, officially named DRB1*1139, was detected while performing HLA-DRB1 high-resolution typing of a volunteer bone marrow donor. DRB1*1139 is identical to DRB1*11011 except at codon 51 (ACG-->AGG) changing the encoded Threonine to Arginine. The triplet AGG has never been found in any other DRB1 allele. In fact, with standard polymerase chain reaction (PCR) amplification with sequence specific primers, the presented allele would have been interpreted as DRB1*1101 (Note).

Identification of a novel HLA-B allele--HLA-B*4902

We report herein the identification of HLA-B*4902. This new allele was identified in a Caucasian individual serologically typed as B49. The allele codifying for this antigen was not clearly detectable with polymerase chain reaction using sequence-specific primers (PCR-SSP) because of an atypical amplification pattern. DNA sequencing demonstrated the presence of a new variant due to two nucleotide substitutions (from G to C and from T to C) in exon 2 at nucleotides 309 and 311 respectively. These substitutions would result in a silent mutation and in one amino acid substitution from Ile to Thr, respectively.

Intellectual assessment of children with asymptomatic congenital cytomegalovirus infection

The findings of previous studies examining the neurocognitive development of children with clinically inapparent (asymptomatic) cytomegalovirus (CMV) infection have demonstrated mixed results. These studies have generally depended on small sample sizes (i.e., < 50). We examined the intellectual development of children with asymptomatic congenital CMV infection using a sample larger than previous studies. Two hundred and four cases aged 5 to 200 months were compared with 177 uninfected siblings ranging in age from 6 to 203 months. Parents were administered the Developmental Profile, a measure of developmental achievement. Children who were older than 30 months were administered an objective intelligence measure. Results of this study showed that children with asymptomatic congenital CMV infection do not demonstrate intellectual impairment, and that they perform similarly to uninfected siblings. Parents tended to overestimate their child's level of functioning regardless of whether the child had CMV infection.