Final answer:
Repeat expansions in Huntington's disease can occur during maternal transmission. HD is an autosomal dominant genetic disorder with each child having a 50 percent chance of inheriting it. The disease is characterized by abnormal huntingtin protein with elongated glutamine residue sequences.
Step-by-step explanation:
The question asks about repeat expansions in the maternal transmission of Huntington's disease (HD). Huntington's disease is an autosomal dominant genetic disorder, which means that each child of an affected parent has a 50 percent chance of inheriting the mutant gene. The specifics of maternal versus paternal transmission of repeat expansions are detailed within research beyond the parameters of high school biology, however, some studies suggest that the phenomenon of repeat expansions can occur during maternal transmission, although it can be more frequently observed in paternal transmission.
Huntington's disease is characterized by the production of an abnormal form of the huntingtin protein, due to a mutation that increases the number of glutamine residues. This expansion is due to the repetition of CAG trinucleotide sequences in the gene encoding for this protein. The length of the repeat is associated with the severity and the onset age of the disease symptoms, which include physical, psychological, and cognitive decline.
It is important to note that Huntington's Disease is not related to hemolytic disease of the newborn (HDN), which is a condition that can occur when there is an incompatibility between the blood types of the mother and fetus. Despite both conditions being identified with the acronym 'HD,' they are separate diseases with different causes and mechanisms.