NEW STUDY! Parasym Plus™ for Multiple Sclerosis › Forums › PrettyIll.com Discussion › Vision › Family history of eye rupture › Reply To: Family history of eye rupture
That is good. It is always good news to have a doctor willing to learn. I found this referring to a lab test that can be orders on a random urine sample. It also describes type 6. I don’t know is this helps or not, but maybe your PCP could order this or you could see a dermatologist for a skin biopsy and maybe they could order the urine test too.
Shonda
Yellow top conical tube (no additive)
Minimum:
Preferred Minimum: 4 mL first-morning void or random urine
Absolute Minimum: 3 mL first-morning void orrandom urine
Delivery Instructions:
Deliver to laboratory immediately after collection.
Turn Around Time:
2 weeks upon receipt at reference laboratory
Reference Range:
Age PYR DPYR Ratio DPYR/PYR
0-11 months Not applicable Not applicable 0.13-0.20
1-3 years Not applicable Not applicable 0.18-0.24
4-9 years Not applicable Not applicable 0.19-0.25
10-14 years Not applicable Not applicable 0.17-0.27
15-19 years Not applicable Not applicable 0.20-0.26
20 years and older Not applicable Not applicable 0.23-
0.29
Test Limitations:
Ehlers-Danlos Syndrome (EDS) describes a heterogeneous group of
connective tissue disorders. EDS VI, also known as the kyphoscoliotic
type, is characterized by hyperextensible skin, joint laxity,
progressive scoliosis, severe muscle hypotonia at birth, and ocular
fragility. It is caused by a deficiency of the enzyme lysyl
hydroxylase. Lysyl hydroxylase is encoded by a gene located on
chromosome 1p36.3-p36.2 known as procollagen-lysine, 2-oxoglutarate
5-dioxygenase 1 (PLOD1). This enzyme is essential for the hydroxylation
of lysine residues on collagen. The derived hydroxylysine residues are
the precursors of the most stable crosslinks of collagen, pyridinoline,
and deoxypyridinoline.
The incidence of EDS VI has been estimated at 1 in 100,000 with a
carrier frequency of 1 in 150. It is inherited in an autosomal
recessive manner. Although 20 different mutations have been detected in
the PLOD1 gene, mutation analysis is only being performed on a research
basis. The diagnosis of EDS VI is performed using HPLC to determine the
ratio of deoxypyridinoline to pyridinoline in urine. A markedly
elevated ratio is indicative of the disease. The diagnosis can be
confirmed by enzyme assay in cultured dermal fibroblasts.
Affected fetuses are at risk for premature rupture of membranes and 30
percent have clubfoot. Infants usually present with generalized joint
laxity and muscle hypotonia. Gross milestones, such as walking, may be
delayed. Thoracic scoliosis is common in childhood and often progresses
into the moderate to severe range. All affected individuals have
hyperelastic skin, 60 percent have abnormally thin wide scarring, and
50 percent experience severe bruising. Most affected individuals have
high myopia and microcornea, while a minority have ocular fragility,
glaucoma, or retinal detachment. Frequent joint dislocations can also
pose a serious problem. Adults with severe kyphoscoliosis may develop
frequent pneumonia and restrictive lung disease. Affected individuals
are at increased risk for aortic dilation/dissection, as well as
rupture of medium-sized arteries.
There are no genotypic/phenotypic correlations that have been
determined in the few affected individuals whose mutations have been
determined. Two pathological variants have been observed in more than
one affected family (gene duplication of 7 exons and Y511X). The most
sensitive and specific manner to establish a diagnosis of EDS VI
remains through biochemical testing.
Affected individuals with kyphoscoliosis should be referred for regular
follow-up with an orthopedic surgeon. Older children, adolescents, and
adults can benefit from a physical therapy regimen to strengthen large
muscle groups, particularly the shoulder girdle. They should undergo
routine screening for inguinal hernia.
Routine ophthalmologic examination may be useful for detection and
management of myopia and glaucoma. Referral to a cardiologist for an
echocardiogram for aortic root measurement is recommended every five
years, even if the initial examination is normal. Antimicrobial
prophylaxis for individuals with mitral valve prolapse and aggressive
blood pressure control is critical. Affected individuals may also
benefit from vitamin C (0.5-10 g per day) to improve muscular strength
and wound healing.
This test should be offered to individuals with clinical symptoms
suggesting EDS VI, such as hyperextensible skin, joint hypermobility,
kyphoscoliosis, easy bruisability, or corneal fragility. All siblings
of individuals deemed affected should also be tested, since they are at
25 percent risk for the same disease. Carrier testing cannot be
performed biochemically or by enzyme assay and is not currently
clinically available through PLOD1 mutation analysis. Prenatal
diagnosis is only available through laboratories that perform custom
DNA analysis for couples who have had a previous affected child with
identified mutations. Genetic counseling should be offered to all
affected individuals and their parents.
The HPLC analysis allows the simultaneous quantitation of pyridinoline
and deoxypyridinoline. In patients with EDS VI, the excretion of
deoxypyridinoline is markedly increased. As a result, the
deoxypyridinoline/pyridinoline ratio is also markedly increased (from
0.2 in normal controls to 4-6 in patients with EDS VI) and allows the
diagnosis.