A Cytogenetic Study of Children With Psychiatric Disorders Javier 1.Escobar
T
HE DEVELOPMENT of techniques permitting the visualization of chromosomal cross-bands has greatly enhanced the field of human cytogenetics. It has led to the exact identification of chromosomes and the detection of subtle chromosomal changes characterizing new clinical syndromes.‘-* The G (Giemsa) and Q (Quinacrine mustard) banding techniques are the most widely used. As a relatively simple and replicable procedure, G banding is the method of choice for clinical application. It is attained by staining the chromosome preparation with Giemsa-like stains. The resulting thick dark staining cross-bands that alternate with lighter ones confer distinctive features to each chromosomal pair. By using elongated chromosomes from late prophase or early metaphase instead of the customary late metaphases, the visual resolution is greatly increased, making it feasible to detect chromosomal changes on different groups of patients. The major psychiatric illnesses are important to study with the new techniques because (1) they have a strong genetic component and (2) an association between chromosomal changes and psychiatric disorders has been proposed. A population of children affected with psychiatric disorders was chosen for the present study since extraneous factors such as drugs, chronic physical illness, and institutionalization are less likely to play a role in the nature-nurture interaction. MATERIALS Thirty
consecutive
Hospitals,
AND METHODS
to the child psychiatry
inpatient
service, University
have been studied. The patients had a thorough physical and psychiatric
mosome preparations Hungerford
admissions
were obtained from lymphocyte
with slight modifications.5
of Minnesota
evaluation.
Chro-
cultures processed according to the method of
For G banding,
3-day-old
slides were stained with Wright
phosphate buffer (94) for 45 min.O An average of five banded mitoses per case were visually analyzed, and a photographically
enlarged karyotype
was obtained
for a detailed analysis of the banding pat-
tern. The patients ranged in age from 3 to 14 years. See Table
I
for diagnostic categories.
FINDINGS
Twenty-nine patients had banding patterns at this level history is summarized below translocation. Her karyotype
normal chromosomal complements and normal of visual resolution. One female patient whose case was found to have a 13/14 balanced chromosomal is illustrated in Fig. 1. CASE HISTORY
The patient was a ICyear-old clinical picture was characterized
female admitted
for evaluation of chronic behavioral difficulties. Her
by severe mood swings, delusions of pregnancy,
auditory hallucina-
From the University of Minnesota Medical School and the Department of Psychiatry, St. PaulRamsey Hospital and Medical Center, St. Paul, Minn. Javier I. Escobar, M.D., M.S.: Assistant Professor o/ Psychiatry. University of Minnesota Medical School: Department of Psychiatry. St. Paul-Ramsqv Hospital and Medical Center. St. Paul. Minn. 0 1976 by Grune & Stratton, Inc.
CornPrehensive Pswhiafry, Vol. 17, No. 2 (March/April), 1976
309
JAVIER
310
Table 1. DSM II (Diagnostic
and Statistical
Diagnoses for 30 Ch’ildren Admitted Inpatient
Service, University
Manual of Mental
I. ESCOBAR
Disorders)
to the Child Psychiatry
of Minnesota
Hospitals Number
of
Cases
Psychosis Schizophrenia, Mental
childhood
5
type
retardation
(as primary
4
diagnosis)
Neurosis Phobic neurosis Depressive neurosis Hysterical
neurosis
Organic brain syndrome Nonpsychotic Specific
1
OBS with epilepsy
1
learning disabilities
Psychophysiologic Psychophysiologic
reaction gastrointestinal
Behavior disorders of childhood Unsocialized
1
disorders
and adolescence
aggressive reaction
4
of childhood
Adjustment
reaction
of adolescence
4
Adjustment
reaction
of childhood
3
Withdrawing
reaction
of adolescence
Hyperkinetic
reaction
of childhood
2 2 30
Total
6
8
16
Fig. 1. G-banded chromosomes chromosomes 13 and 14 (square).
of patient
18 (46xX
D/D
17
Tr.). Note the translocation
including
CYTOGENETIC
STUDY
311
OF CHILDREN
and severe anxiety and withdrawal. Most of these symptoms had an insidious onset and worsened within I year prior to admission. She was the first child of a 36-year-old father and a 34year-old mother whose pregnancy and delivery were uneventful. Family history, aside from the occurrence of seizures and retardation in a maternal cousin, was completely negative. The patient’s younger two siblings were in good health. The main findings on the physical examination were short stature and bilateral coloboma of the iris. The neurologic examination showed hyperactive reflexes. The EEG appeared to be “moderately abnormal with poorly developed background rhythmic theta activity in the frontal and temporal areas compatible with diffuse cerebral dysfunction.” The rest of the physical and laboratory workup was tions,
within normal
limits. On the Wechsler
and a performance
Intelligence
score of 76 were obtained.
childhood type, and borderline
mental
Scale for Children
The patient
retardation.
(WISC)
a verbal score of 82
was diagnosed as having schizophrenia,
Treatment
day) was beneficial, and the patient was placed in an institutional
with phenothiazines
(Stelazine
5 mg
setting for special education.
DISCUSSION
The presence of 1 case of major chromosomal change in this study (1 out of 30) exceeds the expected rate for translocations among live births (1.7 per 1000).7 A connection between chromosomal changes and psychiatric disorders has been supported by previous cytogenetic studies on psychiatric patients.R-‘* The main difficulties with those previous studies were: (1) most of them dealt with samples of adult institutionalized patients with heterogeneous and not clearly defined psychiatric diagnoses; (2) the techniques available only permitted a “gross” analysis of the chromosomes. The incidence of sex-chromosome defects has been found to be higher than that of autosomal, possibly because of the availability of a simple screening technique (sex chromatin). Four reports have appeared in the literature concerning cytogenetic studies of psychiatrically disturbed children. 12-15Three studies focusing on samples of autistic children did not produce significant findings.12-‘4 A fourth study on 700 consecutive admissions to an outpatient child psychiatry clinic showed a surprisingly high percentage of chromosomal defects.15 This appears to be the first study using a chromosome banding technique for the analysis of a psychiatric sample. It is of particular clinical interest because of the presence in 1 of the 5 patients with childhood psychosis of a D/D chromosomal translocation. In contrast with the generally accepted idea of the harmless effect of balanced chromosomal changes, the association between balanced D/D translocations and adverse phenotypic effects has also beeen observed in cases of mental retardation, suggesting that minor chromosomal defects may be present.16*17 The major autosomal defects consistently produce severe mental retardation. Sex-chromosome aberrations do not impair intelligence as much, and they are frequently related to behavioral abnormalities. It may be speculated that behavioral disorders lie somewhere along the continuum between mental retardation and normality and that “minor” chromosomal defects may exist whose detection would depend upon the use of the more elaborate techniques now available. These techniques provide a distinct separation of different chromosomal regions and greatly enhance the optical resolution of the chromosomal image. Figure 2 illustrates this point by comparing elongated banded chromosomes from early metaphase (A), G-banded metaphase chromosomes (B), and the old standard chromosomes (C). Note the tremendous increase in visual resolution that is obtained with the new technique.
312
JAVIER
Chromosome
B
2
10
Chromosome
B
C
I. ESCOBAR
C
Chromosome
18 ‘3 I A
BC
Fig. 2. See text for explanation. A = blowup from early metaphase; B = typical G-banded chromosome; C = standard chromosoma.
REFERENCES 1. Caspersson T, Lindsten J, Zech L, et al: Four patients with trisomy 8 identified by the fluorescence and Giemsa banding techniques. J Med Genet 9:1-7, 1972 2. Escobar JI, Sanchez 0, Yunis JJ: A new syndrome resulting from partial trisomy for the distal segment of chromosome 13. Am J Dis Child (in press) 3. Escobar JI, Yunis JJ: Trisomy for the proximal segment of the long arm of chromosome 13. A new clinical entity? Am J Dis Child (in press) JJ, Escobar JI: Partial trisomy 11 in a child resulting from a complex maternal rearrangement of chromosomes 1I, 12 and 13. Humangenetik 2259-65, 1974 4. Sanchez
0,
Yunis
5. Hungerford DA: Leukocytes cultured from small inocula of whole blood and the preparation of metaphase chromosomes by treatment with hypotonic KCL. Stain Technol40:333-338, 1965 6. Sanchez 0, Escobar JI, Yunis JJ: A simple G banding technique. Lancet 2:263, 1973
7. Ratcliffe SG, Stewart AL, Melville MM, et al: Chromosome studies on 3500 newborn male infants. Lancet 1:121-122, 1970 8. Anders JH, Jagiello G, Polani PE, et al: Chromosome findings in chronic psychotic patients. Br J Psychiatry 114:1167-l 174, 1968 9. Kaplan AR: Chromosomal abnormalities in female schizophrenics. J Nerv Ment Dis 147:402-417, 1968 IO. Polani PE: Abnormal sex chromosomes and mental disorder. Nature 223:68%686, 1969
I I. Forssman H: The mental implications of sex chromosome aberrations. Br J Psychiatry I17:353-363, 1970 12. Book JA, Nichtern S, Gruenberg E: Cytogenetical investigations in childhood schizophrenia. Acta Psychiatr Stand 39:309323.1963 13. Judd LL, Mandell AJ: Chromosome studies in early infantile autism. Arch Gen Psychiatry 18:45(1-457, 1968 14. Wolraich M, Bzostek B, Nev RL, et al:
CYTOGENETIC
Lack
STUDY
313
OF CHILDREN
of chromosome
abberations
in autism.
N
15. Crandall Chromosome a psychiatric
BF,
Carrel
RE,
Sparkes
RS:
findings in 700 children referred to clinic. J Pediatr 80:62-68,
16. Raaijmakers,
D/D
translocations
patients. Humangenetik
Engl J Med283:1231,1970
of
18:288-295.
mentally
17:165-168,
AS: Transmission
translocation
dence of mental
1972
Engelen E: Identification
17. Dekaban ciprocal
in
1966
retarded 1973
of a D/D
re-
in a family with high inci-
retardation.
Am J Hum Gene1
T
HE DEVELOPMENT of techniques permitting the visualization of chromosomal cross-bands has greatly enhanced the field of human cytogenetics. It has led to the exact identification of chromosomes and the detection of subtle chromosomal changes characterizing new clinical syndromes.‘-* The G (Giemsa) and Q (Quinacrine mustard) banding techniques are the most widely used. As a relatively simple and replicable procedure, G banding is the method of choice for clinical application. It is attained by staining the chromosome preparation with Giemsa-like stains. The resulting thick dark staining cross-bands that alternate with lighter ones confer distinctive features to each chromosomal pair. By using elongated chromosomes from late prophase or early metaphase instead of the customary late metaphases, the visual resolution is greatly increased, making it feasible to detect chromosomal changes on different groups of patients. The major psychiatric illnesses are important to study with the new techniques because (1) they have a strong genetic component and (2) an association between chromosomal changes and psychiatric disorders has been proposed. A population of children affected with psychiatric disorders was chosen for the present study since extraneous factors such as drugs, chronic physical illness, and institutionalization are less likely to play a role in the nature-nurture interaction. MATERIALS Thirty
consecutive
Hospitals,
AND METHODS
to the child psychiatry
inpatient
service, University
have been studied. The patients had a thorough physical and psychiatric
mosome preparations Hungerford
admissions
were obtained from lymphocyte
with slight modifications.5
of Minnesota
evaluation.
Chro-
cultures processed according to the method of
For G banding,
3-day-old
slides were stained with Wright
phosphate buffer (94) for 45 min.O An average of five banded mitoses per case were visually analyzed, and a photographically
enlarged karyotype
was obtained
for a detailed analysis of the banding pat-
tern. The patients ranged in age from 3 to 14 years. See Table
I
for diagnostic categories.
FINDINGS
Twenty-nine patients had banding patterns at this level history is summarized below translocation. Her karyotype
normal chromosomal complements and normal of visual resolution. One female patient whose case was found to have a 13/14 balanced chromosomal is illustrated in Fig. 1. CASE HISTORY
The patient was a ICyear-old clinical picture was characterized
female admitted
for evaluation of chronic behavioral difficulties. Her
by severe mood swings, delusions of pregnancy,
auditory hallucina-
From the University of Minnesota Medical School and the Department of Psychiatry, St. PaulRamsey Hospital and Medical Center, St. Paul, Minn. Javier I. Escobar, M.D., M.S.: Assistant Professor o/ Psychiatry. University of Minnesota Medical School: Department of Psychiatry. St. Paul-Ramsqv Hospital and Medical Center. St. Paul. Minn. 0 1976 by Grune & Stratton, Inc.
CornPrehensive Pswhiafry, Vol. 17, No. 2 (March/April), 1976
309
JAVIER
310
Table 1. DSM II (Diagnostic
and Statistical
Diagnoses for 30 Ch’ildren Admitted Inpatient
Service, University
Manual of Mental
I. ESCOBAR
Disorders)
to the Child Psychiatry
of Minnesota
Hospitals Number
of
Cases
Psychosis Schizophrenia, Mental
childhood
5
type
retardation
(as primary
4
diagnosis)
Neurosis Phobic neurosis Depressive neurosis Hysterical
neurosis
Organic brain syndrome Nonpsychotic Specific
1
OBS with epilepsy
1
learning disabilities
Psychophysiologic Psychophysiologic
reaction gastrointestinal
Behavior disorders of childhood Unsocialized
1
disorders
and adolescence
aggressive reaction
4
of childhood
Adjustment
reaction
of adolescence
4
Adjustment
reaction
of childhood
3
Withdrawing
reaction
of adolescence
Hyperkinetic
reaction
of childhood
2 2 30
Total
6
8
16
Fig. 1. G-banded chromosomes chromosomes 13 and 14 (square).
of patient
18 (46xX
D/D
17
Tr.). Note the translocation
including
CYTOGENETIC
STUDY
311
OF CHILDREN
and severe anxiety and withdrawal. Most of these symptoms had an insidious onset and worsened within I year prior to admission. She was the first child of a 36-year-old father and a 34year-old mother whose pregnancy and delivery were uneventful. Family history, aside from the occurrence of seizures and retardation in a maternal cousin, was completely negative. The patient’s younger two siblings were in good health. The main findings on the physical examination were short stature and bilateral coloboma of the iris. The neurologic examination showed hyperactive reflexes. The EEG appeared to be “moderately abnormal with poorly developed background rhythmic theta activity in the frontal and temporal areas compatible with diffuse cerebral dysfunction.” The rest of the physical and laboratory workup was tions,
within normal
limits. On the Wechsler
and a performance
Intelligence
score of 76 were obtained.
childhood type, and borderline
mental
Scale for Children
The patient
retardation.
(WISC)
a verbal score of 82
was diagnosed as having schizophrenia,
Treatment
day) was beneficial, and the patient was placed in an institutional
with phenothiazines
(Stelazine
5 mg
setting for special education.
DISCUSSION
The presence of 1 case of major chromosomal change in this study (1 out of 30) exceeds the expected rate for translocations among live births (1.7 per 1000).7 A connection between chromosomal changes and psychiatric disorders has been supported by previous cytogenetic studies on psychiatric patients.R-‘* The main difficulties with those previous studies were: (1) most of them dealt with samples of adult institutionalized patients with heterogeneous and not clearly defined psychiatric diagnoses; (2) the techniques available only permitted a “gross” analysis of the chromosomes. The incidence of sex-chromosome defects has been found to be higher than that of autosomal, possibly because of the availability of a simple screening technique (sex chromatin). Four reports have appeared in the literature concerning cytogenetic studies of psychiatrically disturbed children. 12-15Three studies focusing on samples of autistic children did not produce significant findings.12-‘4 A fourth study on 700 consecutive admissions to an outpatient child psychiatry clinic showed a surprisingly high percentage of chromosomal defects.15 This appears to be the first study using a chromosome banding technique for the analysis of a psychiatric sample. It is of particular clinical interest because of the presence in 1 of the 5 patients with childhood psychosis of a D/D chromosomal translocation. In contrast with the generally accepted idea of the harmless effect of balanced chromosomal changes, the association between balanced D/D translocations and adverse phenotypic effects has also beeen observed in cases of mental retardation, suggesting that minor chromosomal defects may be present.16*17 The major autosomal defects consistently produce severe mental retardation. Sex-chromosome aberrations do not impair intelligence as much, and they are frequently related to behavioral abnormalities. It may be speculated that behavioral disorders lie somewhere along the continuum between mental retardation and normality and that “minor” chromosomal defects may exist whose detection would depend upon the use of the more elaborate techniques now available. These techniques provide a distinct separation of different chromosomal regions and greatly enhance the optical resolution of the chromosomal image. Figure 2 illustrates this point by comparing elongated banded chromosomes from early metaphase (A), G-banded metaphase chromosomes (B), and the old standard chromosomes (C). Note the tremendous increase in visual resolution that is obtained with the new technique.
312
JAVIER
Chromosome
B
2
10
Chromosome
B
C
I. ESCOBAR
C
Chromosome
18 ‘3 I A
BC
Fig. 2. See text for explanation. A = blowup from early metaphase; B = typical G-banded chromosome; C = standard chromosoma.
REFERENCES 1. Caspersson T, Lindsten J, Zech L, et al: Four patients with trisomy 8 identified by the fluorescence and Giemsa banding techniques. J Med Genet 9:1-7, 1972 2. Escobar JI, Sanchez 0, Yunis JJ: A new syndrome resulting from partial trisomy for the distal segment of chromosome 13. Am J Dis Child (in press) 3. Escobar JI, Yunis JJ: Trisomy for the proximal segment of the long arm of chromosome 13. A new clinical entity? Am J Dis Child (in press) JJ, Escobar JI: Partial trisomy 11 in a child resulting from a complex maternal rearrangement of chromosomes 1I, 12 and 13. Humangenetik 2259-65, 1974 4. Sanchez
0,
Yunis
5. Hungerford DA: Leukocytes cultured from small inocula of whole blood and the preparation of metaphase chromosomes by treatment with hypotonic KCL. Stain Technol40:333-338, 1965 6. Sanchez 0, Escobar JI, Yunis JJ: A simple G banding technique. Lancet 2:263, 1973
7. Ratcliffe SG, Stewart AL, Melville MM, et al: Chromosome studies on 3500 newborn male infants. Lancet 1:121-122, 1970 8. Anders JH, Jagiello G, Polani PE, et al: Chromosome findings in chronic psychotic patients. Br J Psychiatry 114:1167-l 174, 1968 9. Kaplan AR: Chromosomal abnormalities in female schizophrenics. J Nerv Ment Dis 147:402-417, 1968 IO. Polani PE: Abnormal sex chromosomes and mental disorder. Nature 223:68%686, 1969
I I. Forssman H: The mental implications of sex chromosome aberrations. Br J Psychiatry I17:353-363, 1970 12. Book JA, Nichtern S, Gruenberg E: Cytogenetical investigations in childhood schizophrenia. Acta Psychiatr Stand 39:309323.1963 13. Judd LL, Mandell AJ: Chromosome studies in early infantile autism. Arch Gen Psychiatry 18:45(1-457, 1968 14. Wolraich M, Bzostek B, Nev RL, et al:
CYTOGENETIC
Lack
STUDY
313
OF CHILDREN
of chromosome
abberations
in autism.
N
15. Crandall Chromosome a psychiatric
BF,
Carrel
RE,
Sparkes
RS:
findings in 700 children referred to clinic. J Pediatr 80:62-68,
16. Raaijmakers,
D/D
translocations
patients. Humangenetik
Engl J Med283:1231,1970
of
18:288-295.
mentally
17:165-168,
AS: Transmission
translocation
dence of mental
1972
Engelen E: Identification
17. Dekaban ciprocal
in
1966
retarded 1973
of a D/D
re-
in a family with high inci-
retardation.
Am J Hum Gene1
