Table 1.

Molecular Genetic Testing Used in Mucopolysaccharidosis Type III

Gene 1, 2Proportion of MPS III Attributed to Pathogenic Variants in Gene 3Proportion of Pathogenic Variants 4 Detectable by Method
Sequence analysis 5Gene-targeted deletion/duplication analysis 6
GNS 6%~84% 7~16% 7
HGSNAT 4%~98% 8Unknown 9
NAGLU 30%~90% 10Unknown 9
SGSH 60%~98% 11Unknown 9
1.

Genes are listed in alphabetic order.

2.
3.
4.

See Molecular Genetics for information on allelic variants detected in this gene.

5.

Sequence analysis detects variants that are benign, likely benign, of uncertain significance, likely pathogenic, or pathogenic. Variants may include small intragenic deletions/insertions and missense, nonsense, and splice site variants; typically, exon or whole-gene deletions/duplications are not detected. For issues to consider in interpretation of sequence analysis results, click here.

6.

Gene-targeted deletion/duplication analysis detects intragenic deletions or duplications. Methods used may include quantitative PCR, long-range PCR, multiplex ligation-dependent probe amplification (MLPA), and a gene-targeted microarray designed to detect single-exon deletions or duplications. Gene-targeted deletion/duplication testing will detect deletions ranging from a single exon to the whole gene; however, breakpoints of large deletions and/or deletion of adjacent genes (e.g., those described by Champion et al [2010] and Valstar et al [2010a]) may not be detected by these methods.

7.

The detection rate for pathogenic variants in GNS by sequence analysis in 16 individuals with MPS IIID was approximately 84%. The other 16% were exon or large intragenic deletions [Valstar et al 2010a].

8.

The detection rate for pathogenic variants in HGSNAT by sequence analysis in 29 individuals with MPS IIIC was approximately 98% [Ruijter et al 2008].

9.

No data on detection rate of gene-targeted deletion/duplication analysis are available.

10.

In a study of 24 individuals, the detection rate for pathogenic variants in NAGLU was approximately 90% [Valstar et al 2010b].

11.

In DNA analysis of 101 individuals with MPS IIIA, the detection rate for pathogenic variants in SGSH was approximately 98% [Valstar et al 2010c].

From: Mucopolysaccharidosis Type III

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