the hereditary torsion dystonias (dystonia musculorum mans
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248 Dyck et a l. - Po ly neut'Opath y
myelin sheath, most commonly at the poles of Schwann cell nuclei, adja-
cent to Schmidt-Lantermann incisures and near nodes of Ranvier. In
addition, lipid droplets or myelin ovoids with intact myelin lamellae might
additionally be associated with some of the structures mentioned. In some
myelinated and unmyelinated fibers, glycogen particles appeared to be
increased diffusely in the Sohwann cell cytoplasm. Occasionally the axis
cylinders of unmyelinated and myelinated fibers were densely packed
with glycogen granules and mitochondria. These mitochondria as well as
those in Schwann cell cytoplasm were sometimes unusually large and
abnormally structured. We have seen Schwarm cell cytoplasmic lamellar
bodies and aggregates of glycogen particles and mitochondria in the
Schwarm cell cytoplasm of sural nerves from persons without disease of
nerve. These aggregates are smaller and less numerous than in Cases 1
and 2.
The Hereditary Torsion Dystonias (Dystonia Musculorum
Deformans): Geographical Distribution and IQ in Dominant
and Recessive Forms
ROSWELL ELDRIDGE • ANNE HARLAN • IRVING S. COOPER
MANUEL RIKLAN
New York, New York
Personal study of 137 individuals with torsion dystonia (TD), found
by examining 395 members in 87 families, and review of 476 reported cases,
indicates that there are at least two hereditary forms of TD in addition
to the acquired dystonias (Eldridge et al, 1967).
Autosomal recessive TD, with onset generally between the ages of four
and sixteen and a rapid initial course, has been found inhighest frequencyin Ashkenazi Jewish populations. Geographical distribution of this form
of dystonia mirrors the shift in the Ashkenazi population that has occurred
in this century. Eight cases were reported among Polish Jews before 1940
when the average Jewish population of Poland was approximately 3~~mil-lion; no cases have been reported since 1940 when the Jewish population
was reduced to less than 100,000. Conversely, no cases were reported from
Palestine before 1940 but a recent check with neurologic centers in Israel
revealed 27 reports of dystonia.
A recent survey of all neurologic and neurosurgical centers in the
United States indicates the frequency of this recessively inherited disease
in the Jewish population to be 1 in 40,000. If correct, 1 . of every 100 A s h -
kenazi Jews in this country is a carrier of the gene for this trait. .
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E ldrig e et al. - Hereditary Tors ion Dyston ias 249
The autosomal dominant fonn of torsion dystonia is more variable in
its age of onset and clinical course. Torticollis is frequently the initial
symptom in this form.
Families with successive generations affected with this trait have been
reported inmany populations. One large family has been reported from
Sweden but perhaps more interesting from a genetic standpoint is that at
least 3 of the 17 families with the autosomal dominant form in this series
are of French Canadian extraction.
IQ Results
Data obtained on a group of patients with the autosomal recessive form
of TD and their siblings indicate that the gene for recessive TD increases
intelligence. Results of individual and group intelligence and achievement
tests administered by public and private school personnel have been col-
lected for all available patients with autosomal recessive TD and their
siblings. Controls were selected for each patient and each sib on the basis
of similar age, sex, economic background and ethnic background. In
computing results for patients, only those tests administered before onset
of symptoms were used.
To date the study group consists of 24 individuals. Individual IQ
scores in the patient group range from III to 170 with a mean of 131
and a standard deviation of 17.3. The controls for this group have scores
ranging from 92 to 127 with a mean of 113 and standard deviation of 13.8.
The difference between the mean IQ's for these two groups is significantat a level of P = .04. Siblings have scores ranging from 97 to 146 with a
mean IQ of 118 and standard deviation of 11.4. Their control group has
an IQ range of 91 to 127 with mean of 108 and standard deviation of 15.7.
The difference between these two groups is not statistically significant with
p= .09.
Analysis of achievement tests indicate that, in general, both reading
and mathematical performance are higher in patients and sibs than intheir respective control groups. No difference was found between the
mathematical achievement and the reading achievement of patients or
sibs.Contrary to the reported association of TD with mental retardation,
this study of intelligence in a small group of cases of autosomal recessive
TD indicates those with this disorder perform better intellectually than .an
unaffected but otherwise similar population. If there is an intellectual
advantage conferred by the gene, this would explain the gene's high fre-
quency in a population which over many generations may have been un-
usually sensitive to selection based on intelligence.
In contrast to the superior intelligence of the patients with the reces-
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250 Eldridge et al. -:-Hereditary Torsion Dystonias
sive form of TD, families with the dominant trait often include individuals
with below average IQ. These individuals mayor may not have the dys-
tonia trait. Perhaps the low IQ is a consequence of the stigma in the family
rather than a direct effect of the gene for dominant TD. Members of fami-
lies in which this disorder appears in successive generations, whether
affected or not, may have a reduced selection of mates and therefore have
to settle lower in the economic and social strata than otherwise. As the
trait is perpetuated over successive generations, affected and unaffected
individuals may well find themselves in poorer environments, both geneti-
cally and physically. Mental retardation in this setting would be a re-
flection of these generally poorer circumstances rather than a direct con-
sequence of the gene for dominant TD. The decreasing social and economic
fortunes of several families over the three or four generations that the
trait has been present suggests such an explanation.
Acid Maltase Deficiency of Adult Life
ANDREW G. ENGEL
Rochester, Minnesota
In 1959 di Sant'Agnese considered marked cardiac enlargement, gen-
eralized glycogen storage, normal glycogen structure, preserved glycogen-
olysis in liver. and muscle, and death in infancy to be the diagnostic cri-
teria of "cardiomegalia glyccgenica," the disease described by Pompe in1931. However, since Hers' discovery in 1961 of acid maltase deficiency in
infantile cases of generalized glycogenosis, the same enzymatic defect was
also detected in children and adolescents with mild or no cardiac involve"
ment and with a course simulating muscular dystrophy. Altogether 11 such
cases, ranging in age from three to nineteen at the time of diagnosis, have
been reported to date. The object of this presentation is to show that acid. .maltase deficiency can also present as a syndrome of muscular weakness
in adult life. Three adult cases of acid maltase deficiency were studied at
the Mayo Clinic during the past three years. Morphologic and preliminary
biochemical observations in the first case were reported in 1968. Anotherreport of acid maltase deficiency presenting with weakness in adult life
was published in 1968 (Hudgson et al). The Bndings in the second and
third cases studied at the Mayo Clinic are presented herein.
The second patient (Case 2) was a 44-year-old woman WIth slowly
progressive weakness of the truncal and extremity muscles for 13 years.
During this time her calf muscles became slightly enlarged and the serum
creatine phosphokinase was found to be elevated. Muscular dystrophy was