$Unique_ID{BRK03412} $Pretitle{} $Title{Achondrogenesis} $Subject{Achondrogenesis Neonatal Dwarfism Hypochondrogenesis Chondrogenesis Imperfecta Lethal Neonatal Dwarfism Lethal Osteochondrodysplasia Achondrogenesis Type I Houston-Harris Type Achondrogenesis Type IA Parenti-Fraccaro Type Achondrogenesis Type IB Langer-Saldino Type Achondrogenesis Type II Grebe Type Kniest Syndrome Camptomelic Dysplasia Thanatophoric Dysplasia Short Rib Syndrome} $Volume{} $Log{} Copyright (C) 1992 National Organization for Rare Disorders, Inc. 876: Achondrogenesis ** IMPORTANT ** It is possible that the main title of the article (Achondrogenesis) is not the name you expected. Please check the SYNONYM listing to find the alternate names and disorder subdivisions covered by this article. Synonyms Neonatal Dwarfism Hypochondrogenesis Chondrogenesis Imperfecta Lethal Neonatal Dwarfism Lethal Osteochondrodysplasia Disorder Subdivisions: Achondrogenesis, Type I Houston-Harris Type Achondrogenesis, Type IA Parenti-Fraccaro Type Achondrogenesis, Type IB Langer-Saldino Type Achondrogenesis, Type II Grebe Type Information on the following diseases can be found in the Related Disorders section of this report: Kniest Syndrome Camptomelic Dysplasia Thanatophoric Dysplasia Short Rib Syndrome 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 personal physician and/or the agencies listed in the "Resources" section of this report. Achondrogenesis is a very rare disorder that is inherited as an autosomal recessive genetic trait. Major symptoms include extreme short limbed dwarfism, lack of development of ribs and other major bone formation. The head may be either soft or enlarged depending on the type of Achondrogenesis involved. The disorder is often fatal either in utero (in the womb) or shortly after birth. Symptoms Achondrogenesis is characterized by premature birth, accumulation of fluid in the body (fetal hydrops), either a soft or abnormally large head, short neck and trunk. There are extremely short limbs and lack of proper development of the ribs, vertebra and other bones of the skeleton. The abdomen is very prominent. The growth plate is markedly abnormal. The disorder is lethal either in utero or shortly after birth. Other abnormalities that may occur are: cleft palate, corneal clouding, ear deformities and underdeveloped testicles and rectum. Type I Achondrogenesis, Houston Harris Type, is characterized by prematurity, accumulation of fluid in the body, and an excess of amniotic fluid in the womb before birth (polyhydramnios). The head may be soft but of a normal size. The infant may have a very short limbs, lack of development of the bones of the spine, and an extremely short neck. The ribs may show multiple fractures and be very short as are the other bones of the body. The infant is usually stillborn or dies very shortly after birth. Achondrogenesis Type IA Parenti-Fraccaro Type, is another form of Dwarfism. It is the same as the Houston Harris Type in that the baby's head is soft but of normal size. The child is born prematurely and there is an abnormal accumulation of fluid in the body. The baby's bones in the spine, arms and legs are not properly developed. The ribs are also very short but they do not show fractures as do the ribs of the infants with Type I Achondrogenesis. As with Type I Achondrogenesis, the infants are either stillborn or die soon after birth. Type IB Achondrogenesis, Langer-Saldino Type, has the same features as the previous forms of Achondrogenesis, however, it is characterized by an abnormally large head. The size of the infant's head makes delivery very difficult so extreme care is necessary in order to prevent damage to the mother. This form of dwarfism may result in stillborn infants or in less severe cases the infant may survive for weeks or months. This form of Achondrogenesis may also be inherited through autosomal dominant genetic patterns as well as autosomal recessive genetic inheritance. Type II Achondrogenesis, Grebe Chondrodysplasia, is characterized by very shortened limbs, a normal head and chest area. There may be absent or extra fingers or toes, or these digits may be very small. The hands and feet are extremely short and stubby. This Type of Achondrogenesis does not result in death as the chest area is not abnormally small and breathing is not constricted. Causes Achondrogenesis is caused by autosomal recessive inheritance in most instances. However, in the case of Type IB, Langer-Saldino Type, there may be rare cases of autosomal dominant patterns of inheritance. Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother. In dominant disorders a single copy of the disease gene (received from either the mother or father) will be expressed "dominating" the other normal gene and resulting in the appearance of the disease. The risk of transmitting the disorder from affected parent to offspring is fifty percent for each pregnancy regardless of the sex of the resulting child. In recessive disorders, the condition does not appear unless a person inherits the same defective gene from the same trait from each parent. If one receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk of transmitting the disease to the children of a couple, both of whom are carriers for a recessive disorder, is twenty-five 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 Achondrogenesis is a very rare form of dwarfism that affects males and females in equal numbers. The Grebe Type is usually found in a highly inbred Brazilian population and in Miao Chinese. There is also a form that affects certain people of German heritage. Related Disorders Symptoms of the following disorders can be similar to those of Achondrogenesis. Comparisons may be useful for a differential diagnosis: Kniest Syndrome is characterized by extremely short stature with a shortened, barrel-shaped chest. The face is flat with bulging eyes. There may also be a flat nasal bridge, cleft palate and excessive ear infections. The child may also be nearsighted which may lead to retinal detachment. The arms and legs are very short with bowing. There is usually enlargement of the joints causing pain and stiffness. Hernias, loss of hearing and a collapsing trachea may also occur. Camptomelic Dysplasia is another form of growth deficiency. The infant is born with an enlarged head, flat face and nasal bridge, cleft palate and deformed ears. There are short flat vertebrae, small rib cage and incomplete development of bones in the arms and legs. Often there is a lack of development of sexual characteristics. There is central nervous system problems and failure to thrive. If the infant survives the newborn period there will be feeding and breathing problems. Thanatophoric Dysplasia is another form of dwarfism. It is characterized by enlarged head, shortened bones in the arms and legs, small, short ribs and flattened vertebrae. There is an abnormally large amount of amniotic fluid and very little fetal movement. Short Rib Syndrome is a form of short limb dwarfism. The infant has cleft lip and palate, deformed ears, narrow chest with short ribs. The kidneys are often deformed as are the sex organs. There may be brain malformations and an absence of a gallbladder. These infants often die soon after birth as a result of insufficient lung development. Therapies: Standard Ultrasound of the mother in the third trimester can often warn of the condition of the fetus. Treatment of the condition is to maintain the mothers health. Genetic counseling may be of benefit for families. Other treatment is symptomatic and supportive. The National Institutes of Health (NIH) is sponsoring the Human Genome Project which is aimed at mapping every gene in the human body and learning why they sometimes malfunction. It is hoped that this new knowledge will lead to prevention and treatment of birth defects in the future. Therapies: Investigational The Titanium Rib Project is underway to implant expandable ribs in patients with disorders involving missing, underdeveloped or otherwise malformed rib cages, ribs or chest walls. Absent areas due to surgery or birth defects, fused ribs or hypoplastic chests may be improved using the titanium ribs which can be expanded as the child grows. Interested persons may contact: Dr. Robert Campbell Santa Rosa Children's Hospital 519 W. Houwton St. San Antonio, TX 78207-3198 (512) 567-5125 This disease entry is based upon medical information available through September 1992. 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 Achondrogenesis, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 NIH/National Institute of Child Health and Human Development (NICHHD) 9000 Rockville Pike Bethesda, MD 20892 (301) 496-5133 International Center for Skeletal Dysplasia St. Joseph Hospital 7620 York Road Towson, MD 21204 (301) 337-1250 The Magic Foundation 1327 N. Harlem Ave. Oak Park, IL 60302 (708) 383-0808 Human Growth Foundation 7777 Leesburg Pike P.O. Box 3090 Falls Church, VA 22043 (703) 883-1773 (800) 451-6434 Parents of Dwarfed Children 11524 Colt Terrace Silver Spring, MD 20902 Little People of America P.O. Box 633 San Bruno, CA 94066 (415) 589-0695 Short Stature Foundation 17200 Jamboree Rd., Suite J Irvine, CA 92714-5828 (714) 474-4554 800-24 DWARF For Genetic Information and Genetic Counseling Referrals: 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, 9th Ed.: Victor A. McKusick, Editor: Johns Hopkins University Press, 1990. Pp. 994-996. SMITH'S RECOGNIZABLE PATTERNS OF HUMAN MALFORMATION, 4th Ed.: Kenneth L. Jones, M.D., Editor; W.B. Saunders Co., 1988. Pp. 281, 286, 290, 296, 312. BIRTH DEFECTS ENCYCLOPEDIA, Mary Louise Buyse, M.D., Editor-in-Chief, Blackwell Scientific Publications, 1990. Pp. 8, 9, 10, 813. ACHONDROGENESIS TYPE II (LANGER-SALDINO) IN ASSOCIATION WITH JUGULAR LYMPHATIC OBSTRUCTION SEQUENCE., Wenstrom, Kd, et al.; Prenat Diagn, July, 1989, (issue 9 (7)). Pp. 527-532. TYPE II ACHONDROGENESIS-HYPOCHONDROGENESIS: MORPHOLOGIC AND IMMUNOHISTOLOGIC STUDIES., Godfrey, M., et al.; Am J Hum Genet, December, 1988 (issue 43 (6)). Pp. 894-904. ACHONDROGENESIS TYPE I: DELINEATION OF FURTHER HETEROGENEITY AND IDENTIFICATION OF TWO DISTINCT SUBGROUPS., Borochowitz, Z., et al.; J Pediatr, January, 1988 (issue 112 (1)). Pp. 23-31.