New Genetic Disease Discovered Affects Primarily Ashkenazi Jews

The National Foundation for Jewish Genetic Diseases. Inc. and Hadassah, today announced plans for jointly coordinating their efforts to combat a new genetic disorder that, at the present time, affects primarily Ashkenazi Jews. The announcement was made by Faye L. Schenk, chairman of the Hadassah Medical Organization, at Hadassah’s 62nd annual National Convention meeting at the Washington Hilton Hotel.

A team of doctors from Hadassah Hospital in Jerusalem has been actively engaged for the past three years in delineating a new genetic disorder affecting Ashkenazi Jewish children. Cloudy cornea in newborn babies or young infants is the earliest clinical sign; later, toward the end of the first year of life, psychomotor retardation becomes apparent.

The disease was first detected in a seven-month-old boy in Jerusalem, and this case reported in the Journal of Pediatrics in April 1974. Since then, four more children (both boys and girls) have been diagnosed ir. Israel; in all of the families, a large proportion of the antecedents has originated in Eastern Europe, mainly central or southern Poland.

The true genetic nature of this disorder has only come to light during the past year. Three additional cases have recently been diagnosed in the United States, one each in New York, Chicago and Los Angeles. Two additional suspect cases are being studied in London and Los Angeles. Nine of the ten cases are proven Ashkenazi Jews; the family origin of the tenth has not yet been determined.

IDENTIFIED AS MUCOLIPIDOSIS IV

The disease has been named Mucolipidosis IV, based on the appearance of biopsy material as it appears under the electron microscope. The electron microscopic pictures show two kinds of abnormal storage bodies, one similar to mucopolysaccharide diseases such as the Hurler and Hunter syndromes, and the other resembling lipid storage bodies such as those found in Tay-Sachs disease.

Several other storage diseases show similar ultra-structural abnormalities under the electron microscope and have been grouped together under the name of Mucolipidoses. This one has been called Type IV because it differs clinically from all the others.

In addition to cloudy corneas, there are other ocular and clinical signs. These include esotropia (squint or “crossed eyes”) and, later in life, retinal degeneration. Consequently these patients have poor visual acuity, usually no more than counting fingers at two or three feet. But most of all, they are profoundly retarded. They are unable to walk except with support, do not form words, and after some years, have little or no awareness of their environment. By contrast, there are no skeletal changes, either obvious or by X-ray examination. The oldest known patient is a 23-year-old male.

Although the disorder cannot be treated, and the carriers (except for those already having had an affected child) still cannot be detected, much can be done to prevent the birth of these children in the future, doctors say, Ashkenazi Jewish families with profoundly retarded children, and cloudy cornea, who plan to have future children should be tested.

If they have cloudy corneas and/or retinal changes of the kind described above, a conjunctional biopsy should be performed, and the tissue examined by electron microscopy. If abnormal storage bodies are present, it is likely that this child may have Mucolipidosis IV. Knowing this, future pregnancies can be monitored, and prospective parents counseled.

WHY MISSED IN THE PAST

Why has this disease been missed in the past? There are many reasons, Hadassah and Foundation experts say. For one, the clinical signs are much more subtle than in disorders such as Tay-Sachs disease. Another reason is that the detection had to await advances in the understanding of genetic storage diseases, and the use of conjunctival biopsies for their diagnosis. Finally, a disease caused by a mutant gene in an Ashkenazi Jewish population would appear where there is a sizeable community and a medical center able to diagnose through use of sophisticated techniques such as are available at Hadassah.

George Krohn, president of the National Foundation for Jewish Genetic Diseases, formed to combat other genetic disorders, announced that the Foundation which concerns itself with six other diseases. Dysautonomia, Dystonia, Tay-Sachs, Gauchers, Broom’s Syndrome and Niemann-Pick, will now include Mucolipidosis IV as the seventh. Hadassah and the Foundation will work closely together in the areas of public information, referrals, and continuing research into this newest genetic disorder, the two organizations announced.