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Chapter 31: Child Psychiatry
2 months of age, at a regular pediatric visit, a systolic heart murmur
was heard and electrocardiography (ECG) revealed a mitral valve pro-
lapse. Because Dylan was not cyanotic and had no other cardiac symp-
toms, no treatment was recommended except monitoring. Although
Dylan became less fussy over time, he remained very active, did not
sleep through the night, and was a picky eater, refusing solid foods.
Milestones were slightly delayed, with Dylan sitting unas-
sisted at 10 months and walking at 18 months. Language was also
delayed, and, although his first words appeared at 20 months, Dylan
had always made his wants and needs known. Dylan’s parents were
concerned about his activity level and his developmental delays
compared with his sister; however, they were reassured by the pedia-
trician’s sense that boys often develop more slowly than girls in the
first two years.
When Dylan was 3 years of age, his preschool teacher noted
that he was unable to pay attention and he was hyperactive com-
pared to his classmates, prompting his parents to obtain a devel-
opmental evaluation. Results showed modest delays in cognitive,
linguistic, and motor functioning, with a developmental quotient
(DQ) of 74. Dylan was described as inattentive, shy, and anxious,
and he had poor eye contact. Enrolled in a special kindergarten,
Dylan remained in a combination of special education and main-
streamed classes throughout his academic life.
At 7 years of age, the school psychologist evaluated Dylan and
results indicated that he met criteria for a “learning disability”profile.
Dylan had an overall IQ of 66, with close to average functioning in
short-term memory and pronounced deficits in long-term memory,
expressive language, and visual-spatial functioning. Dylan struggled
with writing tasks and arithmetic, but loved science. Due to his signif-
icant problems with inattention and hyperactivity, Dylan was placed
on Concerta, which was beneficial, and titrated up to 54 mg per day.
He displayed transient, intense interests in unusual items, such as
vacuum cleaners. When Dylan reached the older elementary grades,
he began to have more difficulty socially, and he was bullied about
being in special education, and teased for his long head and big ears.
As he entered adolescence, Dylan became increasingly anxious,
so much so that he occasionally rubbed his hands or rocked, and he
“fretted” about day-to-day issues and what would happen next. His
long-term sensitivities to loud sounds seemed to wane slightly, but
he developed fears of storm clouds and dogs and refused to ride on
elevators. He became tearful and upset after his older sister left for
a party, and worried that she might have a car accident. Dylan was
very shy and would occasionally pace with worry and complain
of stomachaches, but he attended school and had a small group of
acquaintances in the Special Olympics bowling league. He enjoyed
activities that did not involve much talking or sustained attention.
When Dylan was 17 years of age, his parents happened to watch
a television documentary on genetic causes of intellectual disability.
They were overwhelmed by the similarities between Dylan and some
of the people described in the program. They later described the expe-
rience as a “jolt.” They had always accepted Dylan, quirks and all,
and had stopped pushing their doctors for reasons “why” when Dylan
was a preschooler. Nevertheless, they immediately called the informa-
tional number offered in the show, and within 2 months, they had the
genetic tests done that confirmed a diagnosis of fragile X syndrome.
Although Dylan’s day-to-day life did not change dramati-
cally after the diagnosis, his parents reported a big difference in
their approach to his shyness, restricted interests, and inatten-
tion. Dylan was later treated for anxiety with a selective sero-
tonin reuptake inhibitor (SSRI) antidepressant, which decreased
his social anxiety and facilitated activities with a few peers.
Dylan’s parents reported a mixture of feelings at having such a
late diagnosis—disappointment in their doctors, relief in finally
knowing, and twinges of guilt. They were energized by Dylan’s
positive responses to treatments for his attentional and anxiety
symptoms and were pleased with Dylan’s recent increased interest
in sharing activities with classmates and peers.
Laboratory Examination
Laboratory tests that may elucidate the causes of intellectual
disability include chromosomal analysis, urine and blood test-
ing for metabolic disorders, and neuroimaging. Chromosomal
abnormalities are the single most known common cause of
intellectual disability.
Chromosome Studies
Chromosome analysis is commonly obtained when multiple
physical anomalies, developmental delays, and intellectual dis-
ability present together. Current techniques are able to chro-
mosomal regions with specific fluorescent in situ hybridization
(FISH) markers, leading to microscopic deletions being identi-
fied in up to 7% of persons with moderate to severe intellec-
tual disability. A history of growth retardation, the presence of
microcephaly, a family history of intellectual disability, short
stature, hypertelorism, and other facial abnormalities increase
the risk for finding subtelomeric defects.
Amniocentesis, in which a small amount of amniotic fluid
is removed from the amniotic cavity transabdominally at about
the 15 weeks of gestation, has been useful in diagnosing pre-
natal chromosomal abnormalities. Its use is considered when
an increased fetal risk exists, such as with increased maternal
age. Amniotic fluid cells, mostly fetal in origin, are cultured for
cytogenetic and biochemical studies.
Chronic villi sampling (CVS) is a screening technique to
determine fetal chromosomal abnormalities. It is done at 8 to
10 weeks of gestation, 6 weeks earlier than amniocentesis is
done. The results are available in a short time (hours or days)
and, if the result is abnormal, the decision to terminate the preg-
nancy can be made within the first trimester. The procedure has
a miscarriage risk between 2 and 5 percent; the risk in amnio-
centesis is lower (1 in 200). A non-invasive blood test called
materniT21 is a proprietary prenatal test that detects abnormali-
ties of chromosomes 21,18,13, X and Y. It is highly specific for
Down syndrome (Figure 31.3-1). There is no risk of miscarriage.
Urine and Blood Analysis
Lesch-Nyhan syndrome, galactosemia, PKU, Hurler’s syn-
drome (Figure 31.3-2), and Hunter’s syndrome (Figure 31.3-3)
are examples of disorders characterized by intellectual disabil-
ity that can be identified through assays of the appropriate
enzyme or organic or amino acids. Enzymatic abnormalities in
chromosomal disorders, particularly Down syndrome, promise
to become useful diagnostic tools.
Electroencephalography
Electroencephalography is indicated whenever a seizure disor-
der is considered. “Nonspecific” EEG changes, characterized by
slow frequencies with bursts of spikes and sharp or blunt wave
complexes are found with greater frequency among populations
