CASE 81
By: Dr. Amna Kashgari MD,SSC-Rad
HISTORY: A 5-year-old boy with short stature and dysmorphic features.
What are your findings?
What is your diagnosis?
FINDINGS:
Anteroposterior (AP) pelvic radiograph (A) demonstrates flared ilium laterally with inferior constriction (wine-glass shape). Lateral radiograph of the spin (B) shows thoracolumbar kyphosis with hypoplastic vertebra at thoracolumbar junction results in gibbus, anterior inferior vertebral bodies beaking are noted. Anteroposterior (AP) radiograph of wrist (C) shows short and wide metacarpals with proximal pointing. Note the Madelung’s deformity of the hands with tilting of distal radii and ulna towards each other.
DIAGNOSIS:
Mucopolysaccharidosis.
PEARLS AND DISCUSSION:
The mucopolysaccharidoses (MPS) are a group of heritable lysosomal storage disorders caused by a deficiency in glycosaminoglycan (GAG)-degrading enzymes. It results in accumulation of different types of mucopolysaccharides in cells, tissues and organs throughout the body.
All these disorders are inherited as autosomal recessive traits except for Hunter syndrome, which is an X-linked recessive trait.
Clinically, patients with MPS share a variety of symptoms include distinctive “coarse” facial features, and abnormalities of the skeleton especially joint problems. Extraskeletal manifestations include neurosensory deafness, aortic regurgitation, abdominal hernia and hepatosplenomegaly.
The severity of the different MPS disorders varies greatly among affected individuals, even among those with the same type of MPS and even among individuals of the same family.
They are seven types of:
| Type | Syndrome name | Enzyme deficiency |
|---|---|---|
| I |
Hurler Syndrome ( I H) Scheie Syndrome (I S) |
Alpha-L-iduronidas |
| II | Hunter Syndrome | cell3_2 |
| III |
Sanfilippo syndrome A Sanfilippo syndrome B Sanfilippo syndrome C |
Heparan sulphamidase N-acetyl-glucosaminidase Acetyl-CoA: alpha-glucusaminide acetyltranferase |
| IV |
Morquio syndrome A Morquio syndrome B |
Galactose-6-sulphate sulphatase Beta-galactosidasw |
| V | No longer used was found to be MPS (I S) | |
| VI | Maroteaux-Lamy Syndrome | N-acetylgalactosamine-4-sulphatase |
| VII | Sly Syndrome | Beta-glucuronidase |
Radiological manifestation:
Skull: Macrocephaly, J-shaped sella, frontal bossing.
Spine: Platyspondyly, anterior beaking (central- Morquio and anteroinferior-Hurler/hunter), posterior scalloping, narrowed spinal canal, AAD (atlantoaxial dislocation), kyphosis, scoliosis, Gibbus formation Chest Short, thick clavicles. Oar or paddle shape ribs with narrowing of posterior ends and broadening of anterior end.
Wrist and forearms: Widening of the humerus, radius and ulna in the elbow region with osteoarthitic changes, disproportionally short ulna resulting in ulnar deviation of the hands, bowing of ulna and radius, decreased number of carpal bones and short fourth metacarpals, Madelung’s deformity.
Pelvis and hips: Dysplastic acetabulae, flared ilia, absent femoral heads, short and wide femoral necks, degenerative changes of the hips, an elongated pelvis and a wide symphysis pubis. Subluxation of femoral heads. coxa valga. Long bones Widening/thickening of diaphysis.
FURTHER READING:
Stefano Palmucci & Giancarlo Attinà et al. Imaging findings of mucopolysaccharidoses: a pictorial review. Insights Imaging (2013) 4:443–459
D Rasalkar, W Chu et al. Pictorial review of mucopolysaccharidosis with emphasis on MRI features of brain and spine. The British Journal of Radiology, 84 (2011), 469–477
