Which chromosome abnormalities are most related to holoprosencephaly?

Holoprosencephaly is a neural tube defect characterized by incomplete cleavage of the forebrain, leading to a spectrum of developmental anomalies. Among the chromosome abnormalities associated with holoprosencephaly, trisomies 13 and 18 are particularly significant.

Trisomy 13, also known as Patau syndrome, and trisomy 18, known as Edwards syndrome, both have a strong correlation with holoprosencephaly. The reason for this is related to the underlying genetic disruptions these aneuploidies cause, which can interfere with normal embryonic brain development. In cases of trisomy 13, up to 50% of individuals may present with holoprosencephaly, making it one of the most common genetic conditions associated with this defect. Trisomy 18 is less frequently associated but still presents a notable risk.

The other options, while they do pertain to genetic conditions, have a much weaker or non-existent association with holoprosencephaly. For instance, trisomy 21 (Down syndrome) is not generally linked with this particular anatomical defect in the same manner as the trisomies 13 and 18, and conditions like monosomy X and triploidy