Epidemiology of Holoprosencephaly

January 30, 2016

     Holoprosencephaly can affect the fetus from a mild state to a severe state. Sometimes the body will automatically abort the fetus if it is too severe. There’s significant proportion of mildly affected children surviving past 12 months of age (Solomon, 2013). About half of all infants have chromosomal abnormalities, most often they have trisomy 13.

     The mothers’ age has been associated as a risk factor. Women younger than 25 and older than 35 are at a higher risk for having an infant with holoprosencephaly. 

     Depending on if a child has holoprosencephaly due to a chromosomal abnormality and the type, she may have a recurrence risk for future children. There has been multiple occurrences of holoprosencephaly without chromosomal abnormalities in the same family, which supports genetic or a hereditary basis for at least a portion of the cases.

     The sex of the infant does influence the risk for having holoporsencephaly. It is more common in females than it is in the males.

     Also a case-control study suggests that risk of holoprosencephaly may be increased with maternal use of misoprostol, a synthetic prostaglandin used for elective termination (Birth Defect Risk Factor Series, 2005).

 

References:

Solomon, B. D. (2013, August 29). Holoprosencephaly Overview. Retrieved January 30, 2016, from

     http://www.ncbi.nlm.nih.gov/books/NBK1530/

 

Birth Defect Risk Factor Series: Holoprosencephaly. (2005, November). Retrieved January 30, 2016,

     from http://www.dshs.state.tx.us/birthdefects/risk/risk5-holoprosencephaly.shtm

 

 

 

 

 

 



Now you're wondering what holoprosencephaly is! Let me tell you...

January 24, 2016

Holoprosencephaly is a "disorder caused by the failure of the prosencephalon (the forebrain of the embryo) to divide to form bilateral cerebral hemispheres, causing defects in the development of the face and in brain structure and function."

Okay, okay...That was the technical scientific definition. Let me tell you what it is in every day terms. The brain, while developing between the fourth and sixth week of gestation, does not divide correctly into the left and right brain. Because the brain did not develop properly, there are defects in the brain function and the development of the facial features.

There are three classes of holoprosencephaly that depends on how much the brain was able to divide while it was developing; alobar, semilobar, and lobar.

Alobar holoprosencephaly is when the brain did not divide and is considered the most severe of the three. The baby may not have a recognizable face. It may have one eye or no eyes. It may have a missing nose or a proboscis (a tubular-shaped nose) located above the eye.

Semilobar holoprosencephaly is the brain has somewhat divided. Some of the characteristics would be various degrees of mental retardation, hypotelorism (closely spaced eyes), or have small eyes.

Lobar holoprosencephaly is the mildest case. The brain has divided but there may be a range from mild retardation to normal brain function and have mild or absent facial malformations.

 

 

 http://www.rightdiagnosis.com/h/holoprosencephaly/intro.htm