Autosomal recessive Morquio syndrome B, also referred to as mucopolysaccharidosis type IVB (MPS4B), is caused by mutation in the gene encoding beta-galactosidase (GLB1) (MIM.611458).
Morquio syndrome B is allelic to the various forms of GM1-gangliosidosis (MIM.230500). The latter disorders show central nervous system involvement.
Synopsis
adult height 82-115 cm
short-trunked dwarfism
mildly coarse facial features
prognathism
hearing loss
corneal opacities
broad mouth
widely spaced teeth
grayish enamel
frequent caries
valvular heart disease Aortic valve stenosis
intimal thickening in the coronary arteries
frequent upper respiratory tract infections
restrictive lung disease
flaring of rib cage
prominent sternum
inguinal hernia
mild hepatomegaly
osteoporosis
platyspondyly
odontoid hypoplasia
cervical subluxation
kyphosis
hyperlordosis
scoliosis
ovoid vertebral bodies
coxa valga
constricted iliac wings
joint laxity
genu valgum
ulnar deviation of the wrist
epiphyseal deformities of tubular bones
widened metaphyses
pointed proximal second through fifth metacarpals
normal intelligence
cervical myelopathy
beta-galactosidase deficiency in fibroblasts and white blood cells
keratan sulfate excretion in urine with age
appear normal at birth
onset between 1-3 years
References
Gucev ZS, Tasic V, Jancevska A, Zafirovski G, Kremensky I, Sinigerska I, Nanba E, Higaki K, Gucev F, Suzuki Y. Novel beta-galactosidase gene mutation p.W273R in a woman with mucopolysaccharidosis type IVB (Morquio B) and lack of response to in vitro chaperone treatment of her skin fibroblasts. Am J Med Genet A. 2008 Jun 10. PMID: 18546276