$Unique_ID{BRK04000} $Pretitle{} $Title{Metaphyseal Chondrodysplasia, McKusick Type} $Subject{Metaphyseal Chondrodysplasia, McKusick Type Cartilage-Hair Hypoplasia Cartilage-Hair Hypoplasia with Short-Limbed Dwarfism CHH Hypochondroplasia Metaphyseal Chondrodysplasia, Jansen Type Metaphyseal Chondrodysplasia, Schmid Type } $Volume{} $Log{} Copyright (C) 1989 National Organization for Rare Disorders, Inc. 636: Metaphyseal Chondrodysplasia, McKusick Type ** IMPORTANT ** It is possible that the main title of this article (Metaphyseal Chondrodysplasia, McKusick Type) is not the name you expected. Please check the SYNONYM list to find the alternate names and disorder subdivisions covered by this article. Synonyms Cartilage-Hair Hypoplasia Cartilage-Hair Hypoplasia with Short-Limbed Dwarfism CHH Information on the following disorders can be found in the Related Disorders section of this report: Hypochondroplasia Metaphyseal Chondrodysplasia, Jansen Type Metaphyseal Chondrodysplasia, Schmid Type General Discussion ** REMINDER ** The information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your physician and/or the agencies listed in the "Resources" section of this report. Metaphyseal Chondrodysplasia (McKusick Type) is a progressive genetic bone disorder. It is characterized by progressive short-limbed dwarfism caused by abnormal development of the cartilage at the ends of the long bones. Fine sparse hair on the head, eyebrows and eyelashes also occurs. Symptoms Metaphyseal Chondrodysplasia (McKusick Type) is characterized by progressive short-limbed dwarfism. Bones at the periphery of the body such as hands, feet and knees are primarily affected. Fingers are usually excessively flexible (hypermobile). The spine may be affected. The hair is fine and sparse on the head, eyebrows and eyelashes. Adults with this disorder may reach a height of about 4 feet. Symptoms vary greatly in severity, ranging from mild to severe. Causes Metaphyseal Chondrodysplasia (McKusick Type) is inherited through autosomal recessive genes. Human traits, including the classic genetic diseases, are the product of the interaction of two genes for that condition, one received from the father and one from the mother. In recessive disorders, the condition does not appear unless a person inherits the same defective gene for the same trait from each parent. If a person receives one normal gene and one gene for the disease, he or she will be a carrier for the disease, but usually will show no symptoms. The risk of transmitting the disease to the children of a couple, both of whom are carriers for a recessive disorder, is 25 percent. Fifty percent of their children will be carriers, but healthy as described above. Twenty-five percent of their children will receive both normal genes, one from each parent, and will be genetically normal. Affected Population Metaphyseal Chondrodysplasia (McKusick Type) is a rare disorder affecting males and females in equal numbers. The disorder is more common in Finland than in other countries. It was first identified in Amish communities in the United States Related Disorders Symptoms of the following disorders can be similar to those of Metaphyseal Chondrodysplasia (McKusick Type). Comparisons may be useful for a differential diagnosis: Hypochondroplasia is an autosomal dominant genetic disorder characterized by small stature with disproportionately short limbs. Hands and feet are short and broad. The relative shortening of the limbs may be mild. Mild bowleg and heel abnormalities may also be present. The head tends to be broad, with a prominent forehead. Metaphyseal Chondrodysplasia (Jansen Type), also known as Metaphyseal Chondrodysplasia, Murk Jansen Type, is a rare autosomal dominant genetic disorder characterized by progressive, short-limbed dwarfism. The spine, pelvis and lower legs are distorted. The chin recedes and the fingers are very short. Sclerosis occurs in the skull bones, including those of the inner ear, leading to deafness. Metaphyseal Chondrodysplasia (Schmid Type) is a rare autosomal dominant genetic disorder characterized by moderate, progressive shortening of stature. Bowed legs and a waddling gait also occur. Adult height reaches about 140 cm (4 ft., 8 in.). Therapies: Standard Physiotherapy and orthopedic treatment may be helpful for patients with Metaphyseal Chondrodysplasia (McKusick Type). Genetic counseling may be of benefit for patients and their families. Therapies: Investigational This disease entry is based upon medical information available through April 1989. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. Resources For more information on Metaphyseal Chondrodysplasia, McKusick Type, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 The Magic Foundation 1327 N. Harlem Ave. Oak Park, IL 60302 (708) 383-0808 Human Growth Foundation (HGF) 7777 Leesburg Pike P.O. Box 3090 Falls Church, VA 22043 (703) 883-1773 (800) 451-6434 Little People of America P.O. Box 633 San Bruno, CA 94066 (415) 589-0695 Parents of Dwarfed Children 11524 Colt Terrace Silver Spring, MD 20902 (301) 649-3275 Short Stature Foundation 17200 Jamboree Rd., Suite J Irvine, CA 92714-5828 (714) 474-4554 800-24 DWARF Short Stature Foundation P.O. Box 5356 Huntington Beach, CA 92615-5356 For genetic information and genetic counseling referrals, please contact: March of Dimes Birth Defects Foundation 1275 Mamaroneck Avenue White Plains, NY 10605 (914) 428-7100 Alliance of Genetic Support Groups 35 Wisconsin Circle, Suite 440 Chevy Chase, MD 20815 (800) 336-GENE (301) 652-5553 References MENDELIAN INHERITANCE IN MAN, 7th ed.: Victor A. McKusick; Johns Hopkins University Press, 1986. Pp. 488-489, 1107. THE JANSEN TYPE OF METAPHYSEAL CHONDRODYSPLASIA: CONFIRMATION OF DOMINANT INHERITANCE AND REVIEW OF RADIOGRAPHIC MANIFESTATIONS IN THE NEWBORN AND ADULT: J. Charrow, et al.; American Journal Med Genet (June 1984: issue 18(2)). Pp. 321-327. METAPHYSEAL CHONDRODYSPLASIA, SCHMID TYPE. CLINICAL AND RADIOGRAPHIC DELINEATION WITH A REVIEW OF THE LITERATURE: R.S. Lachman, et al.; Pediatr Radiol (1988: issue 18(2)). Pp. 93-102.