CHT HLA Genetics & Molecular Biology

Question 1

Which chromosome carries the HLA gene complex in humans?

Accepted Answer

Chromosome 6

Answer

The HLA gene complex (MHC) is located on the short arm of chromosome 6 at region 6p21.

Question 2

Which HLA class II loci are considered the most polymorphic and clinically significant for transplantation?

Accepted Answer

HLA-DRB1 and HLA-DQB1

Answer

HLA-DRB1 and HLA-DQB1 are the most polymorphic class II loci and are routinely typed for solid organ transplantation.

Question 3

What term describes the tendency of certain HLA alleles to occur together on the same chromosome more often than expected by chance?

Accepted Answer

Linkage disequilibrium

Answer

Linkage disequilibrium describes the non-random association of alleles at two or more loci on the same chromosome within a population.

Question 4

HLA molecules are encoded by genes in which genomic region?

Accepted Answer

Major Histocompatibility Complex (MHC)

Answer

HLA molecules are encoded by genes within the MHC, which spans approximately 4 Mb on chromosome 6p21.

Question 5

Which feature of HLA class I molecules allows them to present endogenous peptides?

Accepted Answer

Peptide-binding groove formed by alpha-1 and alpha-2 domains

Answer

HLA class I molecules have a peptide-binding groove formed by the alpha-1 and alpha-2 domains of the heavy chain that accommodates 8–10 amino acid peptides.

CHT - Certified Histocompatibility Technologist Practice Test

CHT - Certified Histocompatibility Technologist Practice Test

CHT HLA Genetics & Molecular Biology