Table 1.

Clinical, radiological, and biochemical features of conditions (rickets mimickers) which are often misdiagnosed as rickets

Conditions	Clinical presentation	Radiology	Biochemistry	Extra-skeletal features	Confirmation
Blount's disease	Bowing of lower limbs	Beaking of proximal tibial metaphyses (medial>lateral)	Normal	Obesity	Radiology
	No involvement of upper limbs	Abnormal 'tibio-femoral angle'
	No rachitic rosary	Tibial 'metaphyseal–diaphyseal angle' (>110)
		No cupping/fraying/splaying
Skeletal dysplasias including metaphyseal chondrodysplasia	Disproportionate short stature	Metaphyseal irregularities ("moth-eaten" appearance)	Normal	Heterogenous	Genetic test
	Bowing of lower limbs	Metaphyseal sclerosis		Corneal/lenticular/retinal defects
	Upper limb involvement (±)	Lateral spurs		Sensorineural hearing loss
		Fragmented, dysplastic epiphyses (in epiphyseal dysplasia)		Diabetes, hypothyroidism,
		Platyspondyly/ malformed vertebrae (in spondyloepiphyseal/spondylo-metaphyseal dysplasia)		Renal anomalies, cardiac valvular defects
Progressive pseudorheumatoid dysplasia	Lower limb deformities	No cupping/fraying/splaying	Normal		Genetic test
	Pain over small and large joints	Enlarged epiphyses
	Joint stiffness	Platyspondyly
	Swelling of interphalangeal joints of the hands	Mega os trigonum
Mucopolysaccharidoses	Disproportionate short stature	Bullet-shaped/pointed metacarpals and phalanges Irregular carpal bones	Normal	Coarse facial features.	Urine GAG screening
	Limb deformities	V-shaped configuration between distal ends of radius and ulna		Corneal clouding	Enzyme assay from peripheral blood leucocytes
	Widening of large joints	Oar-shaped anterior widening of ribs		Bushy eyebrows
		Platyspondyly, dysplastic vertebrae, anterior beaking of the vertebral bodies		Thick and waxy skin	Genetic test
				Hepatosplenomegaly
		Odontoid hypoplasia		Cardiac involvement,
		Atlantoaxial subluxation		Mental retardation
				Cytoplasmic granules in lymphocytes (Alder Reilly granules)
Mucolipidosis (type II)	Small for gestational age	Periosteal new bone formation in long bones and ribs	High ALP	Coarse facial features	Enzyme assay
	Disproportionate short stature	Marked osteopenia	High PTH	Dysmorphic facies	Genetic test
		Resorption of scapulae, clavicles, and mandible	Low Pi	Thick, waxy skin
		Short and wide phalanges		Hepatosplenomegaly
		Metaphyseal fraying		Gibbus
		Tiny epiphyses		Multiple gluteal clefts
Jansen's metaphyseal chondrodysplasia	Severe disproportionate short stature	Cupping and fraying of the metaphyses	High calcium	Hypercalcemia	Genetic test
	Limb deformities	Diffuse demineralization and cortical erosion	Low Pi
		Sclerosis of the base of the skull	Low PTH

ALP, alkaline phosphatase; Pi, inorganic phosphorus; PTH, parathyroid hormone.