Stigmata of marfan's syndrome

Stigmata of marfan's syndrome are the following
Findings in Hand

• Positive wrist sign,
• Positive hand sign
• Arachnodactyly

Anthropometry

• Upper segment/lower segment ratio < 0.8
• Arm span—height > 5 cm

Findings in Face

• High arched palate
• Dislocated lens

Findings in Chest

• Pectus excavatum
• Pectus carmatum
• Kyphoscoliosis

What is Metacarpal index (MCI) ?

This is calculated by measuring the average length of the second, third, fourth and fifth metacarpals, and the average midwidth of the same.

The average length of the four metacarpals/ The average midwidth of the four metacarpals

If MCI is > 8.4, it indicates presence of Marfan's svndrome (Normal MCI =15.4 to 7.9).

How will you clinically differentiate between Marfan syndrome and homocystinuria

Marfan's syndrome is characterised by the following

• It is a connective tissue disorder
• It is transmitted as an autosomal dominant trait
• Bones are normal
• Mitral valve prolapse and dilatation of the aortic root and sinus of Valsalva may be present
• There is no mental retardation
• There is superoateral subluxation of the lens

Homocysinuria is characterised by the folowing

• It is an inborn error of metabolism, due to lack of the enzyme cystathionine synthase, leading to accumulation of homocystine and methionine and a deficiency of cystathionine and cystine
• It is transmitted as an autosomal recessive trait
• Mental defect is present
• Osteoporosis is present 
• Medial degeneration of the aorta and elastic arteries may be present
• Arterial  and venous thrombosis can occur
• Inferolateral subluxation of the lens is seen