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Chapter 31: Child Psychiatry
Disorder
Hereditary
Transmission
a
Enzyme Defect
Prenatal
Diagnosis
Intellectual
Disability Clinical Signs
Mannosidosis
A.R.
Mannosidase
+
+
Hepatomegaly, bone
changes, facial
coarsening
Fucosidosis
A.R.
Fucosidase
+
+
Same as above
IV. AMINO ACID METABOLISM
Phenylketonuria
A.R.
Phenylalanine hydroxylase
–
+
Eczema, blonde hair,
musty odor
Hemocystinuria
A.R.
Cystathionine
b
-synthetase
+
+
Ectopia lentis, Marfan-
like phenotype,
cardiovascular
anomalies
Tyrosinosis
A.R.
Tyrosine amine
transaminase
–
+
Hyperkeratotic
skin lesions,
conjunctivitis
Maple syrup urine disease
A.R.
Branched-chain ketoacid
decarboxylase
+
+
Recurrent ketoacidosis
Methylmalonic acidemia
A.R.
Methylmalonyl-CoA mutase
+
+
Recurrent ketoacidosis,
hepatomegaly,
growth retardation
Propionic acidemia
A.R.
Propionyl-CoA carboxylase
+
+
Same as above
Nonketotic
hyperglycinemia
A.R.
Glycine cleavage enzyme
+
+
Seizures
Urea cycle disorders
Mostly A.R.
Urea cycle enzymes
+
+
Recurrent acute
encephalopathy,
vomiting
Hartnup disease
A.R.
Renal transport disorder
–
–
None consistent
V. OTHERS
Galactosemia
A.R.
Galactose-1-phosphate
uridyltransferase
+
+
Hepatomegaly,
cataracts, ovarian
failure
Wilson’s hepatolenticular
degeneration
A.R.
Unknown factor in copper
metabolism
–
±
Liver disease, Kayser-
Fleischer ring,
neurological
problems
Menkes’ kinky-hair disease
X.R.
Same as above
+
–
Abnormal hair, cerebral
degeneration
Lesch-Nyhan syndrome
X.R.
Hypoxanthine guanine
phosphoribosyltransferase
+
+
Behavioral
abnormalities
a
A.R., autosomal recessive transmission; X.R., X-linked recessive transmission.
(Adapted from Leroy JC. Hereditary, development, and behavior. In: Levine MD, Carey WB, Crocker AC, eds.
Developmental-Behavioral Pediatrics
.
Philadelphia: WB Saunders; 1983:315, with permission.)
Table 31.3-3
Impairment in Disorders with Inborn Errors of Metabolism (
continued
)
Acquired and Developmental Factors
Prenatal Period.
Important prerequisites for the overall
development of the fetus include the mother’s physical, psy-
chological, and nutritional health during pregnancy. Maternal
chronic illnesses and conditions affecting the normal develop-
ment of the fetus’s CNS include uncontrolled diabetes, anemia,
emphysema, hypertension, and long-term use of alcohol and
narcotic substances. Maternal infections during pregnancy,
especially viral infections, have been known to cause fetal
damage and intellectual disability. The extent of fetal dam-
age depends on such variables as the type of viral infection,
the gestational age of the fetus, and the severity of the illness.
Although numerous infectious diseases have been reported to
affect the fetus’s CNS, the following maternal illnesses have
been identified to increase risk of intellectual disability in the
newborn.
Rubella (German measles).
Rubella has replaced syphilis
as the major cause of congenital malformations and intellectual
disability caused by maternal infection. The children of affected
mothers may show several abnormalities, including congenital
heart disease, intellectual disability, cataracts, deafness, micro-
cephaly, and microphthalmia. Timing is crucial, because the
extent and frequency of the complications are inversely related
to the duration of the pregnancy at the time of maternal infection.
When mothers are infected in the first trimester of pregnancy, 10
to 15 percent of the children are affected, but the incidence rises
to almost 50 percent when the infection occurs in the first month
of pregnancy. The situation is often complicated by subclinical
