HLA Genetics & Molecular Biology Flashcards
6 cards from real CHT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 HLA Genetics & Molecular Biology flashcards as text
What is the primary function of beta-2 microglobulin (β2m) in HLA class I molecules?
Answer: Stabilizes the alpha chain and is required for surface expression
β2m is a non-covalently associated light chain that stabilizes the HLA class I alpha chain and is essential for proper folding and surface expression.
Which type of HLA typing method directly determines the nucleotide sequence of HLA alleles?
Answer: Sequence-Based Typing (SBT/SBT-NGS)
SBT (Sanger sequencing) and NGS-based methods directly read the nucleotide sequence to assign high-resolution HLA alleles.
An HLA allele designated HLA-A*02:01 indicates what level of resolution?
Answer: Second-field (allele-level) resolution
The two-field nomenclature (e.g., 02:01) specifies the allele group (02) and the specific allele within that group (01), representing allele-level resolution.
Which HLA gene is encoded outside the classical MHC class I region yet is important in NK cell regulation?
Answer: HLA-E
HLA-E is a non-classical class I molecule encoded within the MHC that presents leader-sequence peptides and serves as a primary ligand for NK cell NKG2 receptors.
What does 'cis' configuration refer to in the context of HLA DQ heterodimers?
Answer: Alpha and beta chains encoded on the same chromosome
A cis DQ heterodimer is formed by DQA1 and DQB1 chains encoded on the same parental haplotype/chromosome.
Which molecular typing technique uses allele-specific primers to amplify target HLA sequences?
Answer: SSP (Sequence-Specific Primers)
SSP uses primers designed to amplify only specific alleles or allele groups under defined PCR conditions, providing rapid low-to-intermediate resolution typing.