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. .



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-



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

the hereditary torsion dystonias (dystonia musculorum mans

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