Kaplan + Sadock's Synopsis of Psychiatry, 11e

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Chapter 31: Child Psychiatry

Table 31.3-3 Impairment in Disorders with Inborn Errors of Metabolism ( continued )

Hereditary Transmission a

Prenatal Diagnosis

Intellectual Disability Clinical Signs

Disorder

Enzyme Defect

+

+

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 Ectopia lentis, Marfan- like phenotype, cardiovascular anomalies

Cystathionine b -synthetase

+

+

A.R.

Hemocystinuria

+

Tyrosinosis

A.R.

Tyrosine amine transaminase

–

Hyperkeratotic skin lesions, conjunctivitis

+

+

Maple syrup urine disease

A.R.

Branched-chain ketoacid decarboxylase Methylmalonyl-CoA mutase

Recurrent ketoacidosis

+

+

Methylmalonic acidemia

A.R.

Recurrent ketoacidosis, hepatomegaly, growth retardation

+ +

+ +

Propionic acidemia Nonketotic  hyperglycinemia Urea cycle disorders

A.R. A.R.

Propionyl-CoA carboxylase Glycine cleavage enzyme

Same as above

Seizures

+

+

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 Abnormal hair, cerebral degeneration

+

Menkes’ kinky-hair disease

X.R.

Same as above

–

+

+

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.)

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