DSM+II+1968

20 MENTAL DISORDERS
Hydrocephalus, congenital. Under this heading is included only
that type of hydrocephalus present at birth or occurring soon after
delivery. All other types of hydrocephalus, secondary to other
conditions, should be classified under the specific etiology when
known.
Hypertelorism (Greig's disease). Characterized by abnormal development
of the sphenoid bone increasing the distance between the
eyes.
Macrocephaly (Megalencephaly). Characterized by an increased
size and weight of the brain due partially to proliferation of glia.
Microcephaly, primary. True microcephaly is probably transmitted
as a single autosomal recessive. When it is caused by other conditions
it should be classified according to the primary condition,
with secondary microcephaly as a supplementary term.
Laurence-Moon-Biedl syndrome. Characterized by mental retardation
associated with retinitis pigmentosa, adiposo-genital dystrophy,
and polydactyly.
.5 With chromosomal abnormality
This group includes cases of mental retardation associated with chromosomal
abnormalities. These may be divided into two sub-groups, those
associated with an abnormal number of chromosomes and those with
abnormal chromosomal morphology.
Autosomal trisomy of group G. (Trisomy 21, Langdon-Down disease,
Mongolism). This is the only common form of mental retardation
due to chromosomal abnormality. (The others are relatively rare.)
It ranges in degree from moderate to severe with infrequent cases of
mild retardation. Other congenital defects are frequently present, and
the intellectual development decelerates with time.
Autosomal trisomy of group £.
Autosomal trisomy of group D.
Sex chromosome anomalies. The only condition under the category
which has any significant frequency is Klinefelter's syndrome.
Abnormal number of chromosomes, other. In this category would
be included monosomy G, and possibly others as well as other forms
of mosaicism.
Short arm deletion of chromosome 5—group B (Cri du chat).A
quite rare condition characterized by congenital abnormalities and a
cat-like cry during infancy which disappears with time.