Holoprosencephaly on ultrasound is most commonly associated with which genetic condition?

Holoprosencephaly is the failure of the forebrain to properly divide into the right and left hemispheres, and it can lead to severe structural brain abnormalities. This condition is particularly associated with Trisomy 13, also known as Patau syndrome.

Trisomy 13 is characterized by multiple congenital anomalies, including heart defects, polydactyly, and midline defects such as holoprosencephaly. The high association with holoprosencephaly in Trisomy 13 is due to the chromosomal abnormalities that disrupt normal embryonic development in the early stages.

While other genetic conditions may present with a variety of neurodevelopmental or structural anomalies, they are not as strongly correlated with holoprosencephaly as Trisomy 13. For example, Trisomy 21 is primarily associated with features such as hypotonia, distinct facial features, and intellectual disability, but it does not typically present with holoprosencephaly. Cystic fibrosis mainly affects the respiratory and digestive systems without a direct link to this specific brain malformation. Turner syndrome can also present with various physical and developmental features, but again, it is not known for holoprosencephaly.

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