Leukodystrophy and leukoencephalopathy Code R-172
- Description
- Number Genes
- Prevalence
- Indications and clinical utility
- Test performed and limitations
- Other Specialities
Leukodystrophy is a term for a group of rare diseases characterised by progressive degeneration of the white substance of the brain. The white substance is mainly composed of myelin that protects nerve fibres, facilitating the transmission of electrical signals between nerve cells. In leukodystrophies, this myelin coating is destroyed, causing damage and neurological dysfunction. The symptoms of leukoencephalopathy can vary widely and include cognitive alterations, memory difficulties, behavioural changes and coordination problems. At the motor level, muscle weakness, difficulties in motor control and unsteady gait can be observed. In addition, neurological symptoms may include speech difficulties, tremors and convulsions, with the severity and expression of these symptoms depending on the area of the brain affected and the extent of the disease.
422 genes
1/100.000
Multi-gene panel aimed at the molecular diagnosis of leukodystrophy and leukoencephalopathy.
Method: NGS sequencing, determination of SNVs (Single Nucleotide Variants), small insertions and deletions and CNVs (Copy Number Variants).
Limits: The test is unable to determine the presence of underrepresented somatic events, balanced chromosomal rearrangements, nucleotide expansion events of repeat regions, CNVs <3 contiguous exons. <3 esoni contigui.
Some genes may have low coverage areas, where necessary or upon specific request, within the limits of methodological limitations, sequencing can be completed with alternative methods (Sanger).
Some genes may be duplicated in the genome (pseudogenes), which may invalidate the analysis.
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