Type III Ehlers-Danlos syndrome ... most debilitating form ... article

[Guest guest]

This article states -

" Sixty patients with genetically verified Ehlers-Danlos syndrome ... "

and of that

" Because of rarity of Types VII and VIII,

these two patients were dropped from the analysis. Fifty-eight patients had

Ehlers-Danlos syndrome Types I, II, III, or IV and form the study cohort. "

The only " genetically verified " possible type was vascular yet this article

states that all patients were " genetically verified " which is wrong.

Unfortunately, to me that makes this article worthless to take to any doctor.

Hugs,

B.

HEDS, New Jersey, USA

[Guest guest]

> The only " genetically verified " possible type was vascular yet this

article

> states that all patients were " genetically verified " which is wrong.

> Unfortunately, to me that makes this article worthless to take to any

doctor.

Actually, only the Hypermobile type does not have any genetic testing

associated with it.

http://www.ehlers-danlos.org/News/Nosology.htm

Classical Type

Abnormal electrophoretic mobility of the proa1 (V) or pro a2(V) chains of

collagen type V has been detected in several but not all families with the

Classical Type. Because a highly sensitive screening method has not yet been

developed, the absence of detected abnormalities by biochemical or molecular

analysis does not rule out a defect in collagen type V. In informative

families genetic linkage studies can be used for prenatal and postnatal

diagnosis. Mutation analysis in individuals is being performed on a research

basis. Locus heterogeneity has been documented (Steinmann et al. 1993).

Genetic linkage to intragenic markers of the COL5A1 or COL5A2 genes has been

excluded in some families. Abnormalities in the collagen fibril structure

can be found in many families by electron microscopy [Vogel et al., 1979]; a

" cauliflower " deformity of collagen fibrils is characteristic [Hausser and

Anton-Lamprecht, 1994] but not specific.

Vascular Type

The method of laboratory diagnosis involves: 1) the demonstration of

structurally abnormal collagen type III produced by fibroblasts causing

defective secretion, post-translational over modification, thermal

instability, and/or sensitivity to proteases and 2) the demonstration of a

mutation in the COL3A1 gene [steinmann et al., 1993]. Determination of the

serum level of procollagen type Ill aminopropeptide is experimental because

of biological variability, confounding concomitant conditions, and

analytical modification of the assay necessary for the detection of low

levels [steinmann et al., 1989].

Kyphoscoliosis Type

The recommended laboratory test is the measurement of total urinary

hydroxylysyl pyridinoline and lysyl pyridinoline cross links after

hydrolysis by HPLC, a test which is readily available and has a very high

degree of sensitivity and specificity [steinmann et al., 1995]. The

determination of dermal hydroxylysine is also easy; however determination of

lysyl hydroxylase activity in fibroblasts and/or mutational analysis of the

PLOD gene is performed on a research basis only.

Arthrochalasia Type

The biochemical defect is determined by electrophoretic demonstration of

pNal (I) or pNa2(l) chains extracted from dermal collagen or harvested from

cultured skin fibroblasts. Direct demonstration of complete or partial exon

6 skipping in cDNAs of COL1A1 or COL1A2, respectively, can be performed,

followed by mutation analysis [steinmann et al., 1993].

Dermatosparaxis Type

Biochemical confirmation is based on the electrophoretic demonstration of

pNa1 (I) and pNa 2(l) chains from collagen type I extracted from dermis in

the presence of protease inhibitors, or obtained from fibroblasts.

Determination of N-proteinase activity is performed on a research basis

only.