Marfan syndrome is basically due the defect in collagen
cross-linking that may be responsible
for abnormalities in supporting tissue. It is an autosomal dominant disease.
It is a syndrome comprising a tetrad of features
- Familial (autosomal dominant)
- Lens dislocation (upward)
- Great vessel (aortic or pulmonary) dilatation and dissection
- Long tubular bones.
The arm span is 7.5 cm > height
Lower segment 5cm
more than the upper segment
The abnormalities in marfans syndrome are the following
1. Skeletal abnormalities
a.Stature.
- Tall and thin (asthenic individual)
- Crown to heel height is above average (ie. tall stature).
- Upper segment : Lower segment = < 0.9
- Arm-span > height
- The arm span is more than the height of the patient by at least 5 cm.
c. High arched palate
d.Chest and spine—Pectus carinatum, pectus excavatum,
straight back syndrome, kyphosis, scoliosis
e. Limbs—Long thin limbs and long thin
fingers(Arachnodactyly)
Metacarpal index more than 8.4 this is calculated by taking the
length of 4 metacarpals divided by its width at its midpoint then values are
averaged
f. Joint hypermobility and ligament laxity
Hyperextensible joints (Steinberg’s sign or thumb sign - in
which the thumb when opposed across the palm extends beyond the outer border of
the palm).
Wrist sign
To elicit it the patients is asked
to enclose his wrist with his thumb and little finger of hand then these
digits will overlap
g. Feet—Pes planus, pes cavus, hallux valgus.
B.Subluxation or dislocation of lens upwards and outwards
(look for irldodoncsls).
Other Ocular Defects are the following
- Microcornea
- Cataract
- Strabismus
- Myopia
- Retinal detachment
- Iridodonesis.
- Cardiovascular abnormality
- Cardiac Defects
- Aneurysm of aorta
- Dissection of aorta
- Sinus of Valsalva aneurysm
- Aortic regurgitation
- Mitral or tricuspid valve prolapse syndrome
- Atrial septal defect (ostium secundum)
- Ventricular septal defect
- Dilatation of the pulmonary artery..
