Webster's New World Medical Dictionary

MPS1
Mucopolysaccharidosis type I. See 
Hurler
syndrome.
MPS2
Mucopolysaccharidosis type II. See 
Hunter
syndrome.
MPS3
Mucopolysaccharidosis type III. See
Sanfilippo syndrome.
MPS4
Mucopolysaccharidosis type IV. See
Morquio syndrome.
MRC 1
Medical Research Council. 
2
Medical
Reserve Corps.
MRI
Magnetic resonance imaging.
mRNA
Messenger RNA.
MRSA
Methicillin-resistant Staphylococcus
aureus.
MS
Multiple sclerosis.
MSAFP
Maternal serum alpha-fetoprotein.
MSUD
Maple syrup urine disease.
mtDNA
Mitochondrial DNA.
mucocele
A swelling consisting of an accumula-
tion of mucus. See also 
mucus.
mucocutaneous lymph node syndrome
See
Kawasaki disease.
mucolipidosis
One of a group of storage dis-
eases in which both lipids and substances called
mucopolysaccharides accumulate in the tissues of
the body. Four different mucolipidoses have been
identified, numbered I through IV. All four are lyso-
somal disorders—that is, the lysomes are
organelles within the cell that contain enzymes that
can digest (lyse) substances—and all are inherited
in an autosomal recessive manner.
mucolipidosis I
A type of mucolipidosis that is
characterized by deficiency of the enzyme neu-
raminidase (sialidase). There are two forms of the
disease. One form is characterized by cherry red
spots in the eyes, gradual loss of vision, progressive
debilitating myoclonus (muscle spasms), and nor-
mal intelligence. The other form of the disease, in
addition to featuring the symptoms of the first form,
causes a coarse face, bony abnormalities, and
sometimes early death. Also known as sialidosis.