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Meier-Gorlin syndrome is a condition primarily characterized by short stature. It is considered a form of primordial dwarfism because the growth problems begin before birth (intrauterine growth retardation). After birth, affected individuals continue to grow at a slow rate. Other characteristic features of this condition are underdeveloped or missing kneecaps (patellae), small ears, and, often, an abnormally small head (microcephaly). Despite a small head size, most people with Meier-Gorlin syndrome have normal intellect.
Some people with Meier-Gorlin syndrome have other skeletal abnormalities, such as unusually narrow long bones in the arms and legs, a deformity of the knee joint that allows the knee to bend backwards (genu recurvatum), and slowed mineralization of bones (delayed bone age).
Most people with Meier-Gorlin syndrome have distinctive facial features. In addition to being abnormally small, the ears may be low-set or rotated backward. Additional features can include a small mouth (microstomia), an underdeveloped lower jaw (micrognathia), full lips, and a narrow nose with a high nasal bridge.
Abnormalities in sexual development may also occur in Meier-Gorlin syndrome. In some males with this condition, the testes are small or undescended (cryptorchidism). Affected females may have unusually small external genital folds (hypoplasia of the labia majora) and small breasts. Both males and females with this condition can have sparse or absent underarm (axillary) hair.
Additional features of Meier-Gorlin syndrome can include difficulty feeding and a lung condition known as pulmonary emphysema or other breathing problems.
Meier-Gorlin syndrome is a rare condition; however, its prevalence is unknown.
Meier-Gorlin syndrome can be caused by mutations in one of several genes. Each of these genes, ORC1, ORC4, ORC6, CDT1, and CDC6, provides instructions for making one of a group of proteins known as the pre-replication complex. This complex regulates initiation of the copying (replication) of DNA before cells divide. Specifically, the pre-replication complex attaches (binds) to certain regions of DNA known as origins of replication, allowing copying of the DNA to begin at that location. This tightly controlled process, called replication licensing, helps ensure that DNA replication occurs only once per cell division and is required for cells to divide.
Mutations in any one of these genes impair formation of the pre-replication complex and disrupt replication licensing; however, it is not clear how a reduction in replication licensing leads to Meier-Gorlin syndrome. Researchers speculate that such a reduction delays the cell division process, which impairs growth of the bones and other tissues during development. Some research suggests that some of the pre-replication complex proteins have additional functions, impairment of which may contribute to features of Meier-Gorlin syndrome, such as delayed development of the kneecaps and ears.
Changes in these genes are associated with Meier-Gorlin syndrome.
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
These resources address the diagnosis or management of Meier-Gorlin syndrome and may include treatment providers.
You might also find information on the diagnosis or management of Meier-Gorlin syndrome in Educational resources (http://ghr.nlm.nih.gov/condition/meier-gorlin-syndrome/show/Educational+resources) and Patient support (http://ghr.nlm.nih.gov/condition/meier-gorlin-syndrome/show/Patient+support).
General information about the diagnosis (http://ghr.nlm.nih.gov/handbook/consult/diagnosis) and management (http://ghr.nlm.nih.gov/handbook/consult/treatment) of genetic conditions is available in the Handbook. Read more about genetic testing (http://ghr.nlm.nih.gov/handbook/testing), particularly the difference between clinical tests and research tests (http://ghr.nlm.nih.gov/handbook/testing/researchtesting).
To locate a healthcare provider, see How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.
You may find the following resources about Meier-Gorlin syndrome helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines (http://ghr.nlm.nih.gov/ConditionNameGuide) and How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
Ask the Genetic and Rare Diseases Information Center (http://rarediseases.info.nih.gov/gard).
autosomal ; autosomal recessive ; cell ; cell division ; cryptorchidism ; DNA ; DNA replication ; dwarfism ; emphysema ; gene ; hypoplasia ; inherited ; intrauterine growth retardation ; joint ; lower jaw ; microcephaly ; micrognathia ; microstomia ; patella ; prevalence ; pulmonary ; pulmonary emphysema ; recessive ; short stature ; stature ; syndrome ; testes
You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://ghr.nlm.nih.gov/glossary).
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.