Chondrodysplasia Grebe type is a rare

genetic disorder A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorde ...

. It is caused by a mutation to the

GDF5 Growth/differentiation factor 5 is a protein that in humans is encoded by the ''GDF5'' gene. The protein encoded by this gene is closely related to the bone morphogenetic protein (BMP) family and is a member of the TGF-beta superfamily. This gro ...

gene. This mutation may be inherited in an

autosomal recessive In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and ...

pattern.

Signs and symptoms

Chondrodysplasia Grebe type causes both

dwarfism Dwarfism is a condition wherein an organism is exceptionally small, and mostly occurs in the animal kingdom. In humans, it is sometimes defined as an adult height of less than , regardless of sex; the average adult height among people with dw ...

and dysmelia (short limb deformity). It may also cause dental problems. There is significant phenotypic variability between individuals.

Cause

Chondrodysplasia Grebe type is caused by a mutation to the

gene. It is inherited in an

pattern. Because of this, 60% of people with chondrodysplasia Grebe type have

consanguinous Consanguinity ("blood relation", from Latin '' consanguinitas'') is the characteristic of having a kinship with another person (being descended from a common ancestor). Many jurisdictions have laws prohibiting people who are related by blood fro ...

parent A parent is a caregiver of the offspring in their own species. In humans, a parent is the caretaker of a child (where "child" refers to offspring, not necessarily age). A ''biological parent'' is a person whose gamete resulted in a child, a male ...

Diagnosis

Due to the small number of

signs and symptoms Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showi ...

, and rarity, chondrodysplasia Grebe type is hard to diagnose.

Genetic testing Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or ...

, usually

exome sequencing Exome sequencing, also known as whole exome sequencing (WES), is a genomic technique for sequencing all of the protein-coding regions of genes in a genome (known as the exome). It consists of two steps: the first step is to select only the subse ...

, is used to identify the mutation to the

gene.{{Cite web, title=Chondrodysplasia, Grebe Type - Tests - GTR - NCBI, url=https://www.ncbi.nlm.nih.gov/gtr/tests/256850/, access-date=2021-04-14, website=www.ncbi.nlm.nih.gov

References

Genetic diseases and disorders