MillerDieker Syndrome (MDS)

Miller-Dieker syndrome’s (MDS) hallmark is lissencephaly (literally means “smooth brain”), a brain malformation which is characterized by a lack of the normal folds or fissures in the brain and microcephaly (abnormally small head). This explains why MDS was previously termed as lissencephaly syndrome.

The brain malformation leads to developmental delay, intellectual disability, seizures, muscle stiffness, feeding difficulties, and weak muscle tone. The facial features include having a big forehead, small and upturned nares, thick upper lip, small jaw, abnormally shaped ears, and a sunken appearance in the middle of the face. Other children have more severe symptoms such as heart defects, protrusion of abdominal organs through the bellybutton, breathing problems, and kidney malformations. Unfortunately, many children born with MDS do not reach adolescence.

This rare condition is caused by the deletion of multiple genes in the short arm of the 17th chromosome. Most cases are due to spontaneous deletion while 12% is due to an inherited chromosomal abnormality. The eponym is attributed to James Q. Miller, an American neurologist and educator who first described the syndrome in 1963. H. Dieker gave the name lissencephaly syndrome in 1969; it was then renamed as Miller-Dieker syndrome.