Dyggve–Melchior–Clausen syndrome is a rare autosomal-recessive disorder, characterized by progressive spondylo-epi-metaphyseal dysplasia associated with mental retardation. The clinical and radiological findings resembles Morquio disease at the onset of condition, which may hinder its diagnosis. Two siblings with chatacteristic clinical (progressive postnatal dwarfism and mental retardation) and radiological features (irregular lace-like appearance of the iliac crests) are reported.

Key words: Dyggve–Melchior–Clausen syndrome, Spondylo-epi-metaphyseal dysplasia.

A 12-year-old boy was admitted with complaints of not gaining height, with delay in developmental milestone. The patient underwent detailed clinical examination followed by radiographic examination, which revealed skeletal dysplasia. He was the fourth child in birth order with parents having consanguinity. Birth history was normal with average size at birth. Family history revealed except the younger sibling having similar complaints. Height was 98 cm (<-3SD), weight was 12.3 kg (<-3SD percentile), pubic bone-heel distance (lower segment) was 53 cm, an upper segment length was 45 cm and an upper to lower segment ratio was 0.85 (normal ~ 0.9). Head circumference was 44.5 cms (<-3SD) (Fig.1). Mental redardation was present (IQ = 41) with no other neurological signs. Waddling gait was present. His skeletal age was 6 years. An increased anteroposterior chest diameter and kyphoscoliosis was present, and proximal portions of the upper and lower limbs were short. Urine amino acids were normal and there was no urinary excretion of mucopolysaccharides. Radiological findings are detailed in Fig.2.

Fig. 1. Siblings with Dyggve-Mclchior-Clausen Syndrome.

Radiological findings in both cases were similar (Fig.2.)

Fig. 2 Iliac bones are hypoplastic with characteristic irregular lace-like appearance of the iliac crests, Irregular ossification was present on the acetabuli and the acetabular roofs are flat. Femoral necks are short and both epiphyses and metaphyses are irregular causing lateral displacement of the femoral heads. Characteristic doublehumped appearance of vertebral bodies. Epiphyseal and metaphyseal dysplasia is present at both ends of humerus with destruction of shoulder joint.

Dyggve–Melchior–Clausen syndrome (DMC, MIM 223800) needs to be differentiated from its rare variant Smith-McCort dysplasia, mucoploysacchri-dosis, spondyloeiphyseal dysplasia tarda and spon-dylometaphyseal dysplasia (SMD).

Both cases presented here had typical clinical and radiological features of DMC. Clinical and radiological presentation of DMC mimics storage disorder, in particular Morquio’s disease (MPS IV, MIM 253010), but the presence of mental retardation and absence of corneal clouding, hyperextensibility of joints, deafness, valvular disease or mucopolysacchariduria in DMC serves to differentiate the two conditions(1).

Smith-McCort dysplasia is a close variant of DMC with all features resembling the later including the radiological findings except that there is no evidence of mental retardation in the former. Spondyloepiphyseal dysplasia tarda and spondy-lometaphyseal dysplasias can be differentiated from DMC based on their differentiating clinical and radiological features(9,10).

Dr Akhila, Consultant, Radiology, Dr Ram Manohar Lohia Hospital for delineating the typical radiological findings and Dr M N Lal Mathur for pshychomotor evaluation of these children.

Contributors: VG and AK were involved in active case management and review of literature. VG and VD revised the paper for critically important intellectual content. All authors approved the final version to be published.

Funding: None.

Competing interests: None stated.

1. El Ghouzzi V, Dagoneau N, Kinning E, Thauvin-Robinet C, Chemaitilly W, Prost-Squarcioni C, et al. Mutations in a novel gene Dymeclin (FLJ20071) are responsible for Dyggve – Melchior – Clausen syndrome. Hum Mol Gene 2003; 12: 357-364.

2. Rodríguez Rodríguez CM, Pineda Marfa M, Duque R, Cormier-Daire V. Dyggve-Melchior-Clausen syndrome, diagnostic difficulty due to it similarity to Morquio disease. Neurologia 2007; 22: 126-129.

3. Burns C, Powell BR, Hsia YE, Reinker K. Dyggve-Melchior-Clausen syndrome: report of seven patients with the Smith-McCort variant and review of the literature. J Pediatr Orthop 2003; 23: 88-93

4. Kandziora F, Neumann L, Schnake KJ, Khodadadyan-Klostermann C, Rehart S, Haas NP, et al. Atlantoaxial instability in Dyggve-Melchior-Clausen syndrome. Case report and review of the literature. J Neurosurg 2002 ; 96: 112-117.

5. Horton WA, Hecht JT. Disorders involving cartilage matrix protiens. In: Kliegman RM, Jenson HB, Behrman RE, Stanton BF, editors. Nelson Textbook of Pediatrics, 18th ed. Philadelphia: Saunders-Elsevier Publisher; 2007. p. 2873-2877.

6. Toledo SP, Saldanha PH, Lamego C, Mourao PA, Dietrich CP, Mattar E. Dyggve–Melchior–Clausen syndrome: genetic studies and report of affected sibs. Am J Med Genet 1979; 4: 255-261.

7. Beighton P. Dyggve – Melchior–Clausen syndrome. J Med Genet 1990; 27: 512-515.

8. Spranger J, Maroteaux P, Der Kaloustian VM. The Dyggve–Melchior–Clausen syndrome. Radiology 1975; 114: 415-421.

9. Fielder J, Frances AM, Le Merrer M, Richter M, Brenner RE. X-linked spondyloepiphyseal dysplasia tarda: molecular cause of a heritable platyspodyly. Spine 2003; 28: E478-482.