Fibrochondrogenesis

Presentation

Fibrochondrogenesis is a congenital disorder presenting several features and radiological findings, some which distinguish it from other osteochondrodysplasias. These include: fibroblastic dysplasia and fibrosis of chondrocytes (cells which form cartilage); and flared, widened long bone metaphyses (the portion of bone that grows during childhood).

Other prominent features include dwarfism, shortened ribs that have a concave appearance, micrognathism (severely underdeveloped jaw), macrocephaly (enlarged head), thoracic hypoplasia (underdeveloped chest), enlarged stomach, platyspondyly (flattened spine), and the somewhat uncommon deformity of bifid tongue (in which the tongue appears split, resembling that of a reptile).

Cause

The cause of platyspondyly in fibrochondrogenesis can be attributed in part to odd malformations and structural flaws found in the vertebral bodies of the spinal column in affected infants.

Fibrochondrogenesis alters the normal function of chondrocytes, fibroblasts, metaphyseal cells and others associated with cartilage, bone and connective tissues. Overwhelming disorganization of cellular processes involved in the formation of cartilage and bone (ossification), in combination with fibroblastic degeneration of these cells, developmental errors and systemic skeletal malformations describes the severity of this lethal osteochondrodysplasia.

Genetics

Fibrochondrogenesis is inherited in an autosomal recessive pattern.

Omphalocele is a congenital feature where the abdominal wall has an opening, partially exposing the abdominal viscera (typically, the organs of the gastrointestinal tract). Fibrochondrogenesis is believed to be related to omphalocele type III, suggesting a possible genetic association between the two disorders.

Diagnosis

Treatment

Epidemiology

Fibrochondrogenesis is quite rare.

A United Arab Emirates (UAE) University report, from early 2003, evaluated the results of a 5-year study on the occurrence of a broad range of osteochondrodysplasias. Out of 38,048 newborns in Al Ain, over the course of the study period, fibrochondrogenesis was found to be the most common of the recessive forms of osteochondrodysplasia, with a prevalence ratio of 1.05:10,000 births.

While these results represented the most common occurrence within the group studied, they do not dispute the rarity of fibrochondrogenesis. The study also included the high rate of consanguinous marriages as a prevailing factor for these disorders, as well as the extremely low rate of diagnosis-related pregnancy terminations throughout the region.

Research

The fibrocartilaginous effects of fibrochondrogenesis on chondrocytes has shown potential as a means to produce therapeutic cellular biomaterials via tissue engineering and manipulation of stem cells, specifically human embryonic stem cells.

Utilization of these cells as curative cartilage replacement materials on the cellular level has shown promise, with beneficial applications including the repair and healing of damaged knee menisci and synovial joints; temporomandibular joints, and vertebra.

References

References

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7. (Jan 1998). "Fibrochondrogenesis in a 17-week fetus: a case expanding the phenotype". American Journal of Medical Genetics.
8. (Jul 1998). "Prenatal ultrasonography: clinical and radiological findings in a boy with fibrochondrogenesis". American Journal of Perinatology.
9. This means that the defective [[gene]] responsible for the disorder is located on an [[autosome]], and two copies of the gene — one copy inherited from each parent — are required in order to be born with the disorder. The parents of an individual with an autosomal recessive disorder each [[genetic carrier. 282520
10. Chen CP. (Jan 2007). "Syndromes and disorders associated with omphalocele (III): single gene disorders, neural tube defects, diaphragmatic defects and others". Taiwan J Obstet Gynecol..
11. (Feb 2003). "Birth prevalence and pattern of osteochondrodysplasias in an inbred high risk population". Birth Defects Research. Part A, Clinical and Molecular Teratology.
12. (May 2008). "Fibrochondrogenesis of hESCs: Growth Factor Combinations and Cocultures". Stem Cells and Development.
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14. (Jan 2004). "Fibrochondrogenesis of free intraarticular small intestinal submucosa scaffolds". Tissue Engineering.