Spondyloenchondrodysplasia

Spondyloenchondrodysplasia is a rare autosomal recessive skeletal dysplasia with vertebral dysplasia and enchondroma-like lesions in the pelvis and long bones. The vertebral bodies show dorsally accentuated platyspondyly with disturbance of ossification. Clinical abnormalities such as short stature, rhizomelic micromelia, increased lumbar lordosis, barrel chest, facial anomalies, and clumsy movements may be present. We report on four patients, three of them from one family, who showed a wide range of clinical and radiological changes to document considerable variability of expression of the mutated gene.

and weighed 28-4 kg. He had rhizomelic micromelia with an arm span of 104 cm and an upper segment/lower segment ratio of 1-3 (+11 SD). His hands and feet were short and plump with broad thumbs. Calcaneovalgus deformity and clinodactyly of the fourth and fifth toes were noted, and the right foot was internally rotated. There was genu valgum, cubitus valgus, barrel chest, pectus carinatum, increased lumbar lordosis, a short neck, and relative macrocephaly (52.5 cm). The face was oval shaped and expressionless with a prominent premaxillary region, frontal bossing, depressed and broad nasal bridge, short nose, anteverted nostrils, and long philtrum. Body movements were clumsy and the gait was waddling.
Laboratory findings included normal serum levels of growth and thyroid hormone, urinary acid mucopolysaccharides, and normal parameters of calcium metabolism.
Radiographs were available from the age of six weeks to 12 years: at all ages the tubular bones were shortened. During infancy, metaphyseal irregularities and widening were present (   The metaphyseal margins are irregular. In (a) and (c) (the brothers) the metaphyses are splayed, the epiphyses are slightly irregular, and there is proximal overgrowth ofthefibulae (not seen in other cases). In (b) the metaphyses are slightly widened and cupped. Radiolucent areas are seen in the distal thirds ofthefemoral and tibial diaphyses and in thefibular metaphyses. The metaphyseal margins are irregular.
were flat with structural densities in their dorsal parts. In later childhood the end plates were slightly irregular. The skull was normal.  1) and laboratory and radiographical findings (figs 3c, Sb, 6c) were similar to those of his brother. CASE 3 UP was a boy born in 1972 to parent aged 23 and 20 years. They and two younger sibs were healthy. Birth length was 51 cm and weight 3100 g. When he was four months old severe craniotabes and mild costochondral beading were noticed and a diagnosis of rickets was made, in spite of normal serum  2) and weighed 31-5 kg. OFC was 53 cm (slightly below average), arm span 142 cm, and upper segment/lower segment ratio 0*9 (-0.5 SD). Except for an accentuated lumbar lordosis and mild turricephaly no dysplastic signs were found. Laboratory findings, including MPS urinary excretion and calcium metabolism, were normal.
Radiographs showed irregular metaphyses from infancy up to the age of 12 years; several of them were splayed and mildly clubbed (fig 3d). In later childhood the vertebral bodies (fig 6d) were flat and markedly dysplastic.  8) supporting autosomal recessive inheritance. CASE 4 AS, a boy born in 1966, was probably the incestuous product of a father-daughter union. At his birth his parents were 17 and 40 years old; they and a younger sister were reportedly healthy. Pregnancy was said to be normal but birth was complicated by premature rupture of the membranes and umbilical cord strangulation possibly causing perinatal asphyxia. Birth length was 50 cm and weight 2550 g. He learned to walk and speak at three years of age.
At six years (fig 9) he was 109 cm tall (-2 SD) ( fig  2) and weighed 16*3 kg. He had spastic quadriplegia with severe foot drop, contractures of the hips and knees, and kyphoscoliosis. His joints were prominent and his hands short and broad. His face was unusual with a broad nasal bridge, a long nose, FIG  and slight retrognathia. Apart from slightly increased serum alkaline phosphatase and hypochromic anaemia laboratory findings were normal.
Radiographs showed slightly shortened tubular bones with wide, cupped metaphyses and radiolu-  (fig 3b, 4b). Some epiphyses were irregular in structure or shape. The scapulae were irregular. The basilar portions of the iliac bones were hypoplastic and the pubic bones and iliac crests were studded with radiolucent lesions (fig 5a). The vertebral bodies (fig 6b) were flat and dysplastic.
The base of the skull was sclerotic.

Discussion
Based on 12 published observations,'6 including two cases of 'autosomal recessive spondylometaphyseal dysplasia' reported by Gustavson et (table).
Most patients are short with disproportionately short limbs in severe cases. In others, body length and proportions are in the lower normal range. Increased lumbar lordosis, kyphoscoliosis, barrel chest, genu valgum or varum; short and broad hands, dolichocephaly, turricephaly, frontal bossing, and mild midface hypoplasia are occasional findings. Joints may be prominent or painful.
The age at manifestation varies from birth to later infancy. Clinical and radiographical abnormalities are not necessarily correlated. Thus, our case 3 had severe platyspondyly but was not short in stature.
Radiographs show mild to severe platyspondyly which is often dorsally accentuated. Localised ossification defects are sometimes present in the dorsal portions of the vertebral bodies. In adolescence, the vertebral abnormalities tend to improve.
The tubular bones are shortened and the metaphyses irregular and slightly widened with varying radiolucent lesions. Usually, the proximal fibular and distal ulnar metaphyses are more severely affected. Sometimes radiolucent areas are present in the diaphyses, epiphyses, iliac crest, scapulae, and sternum. The epiphyses may be irregular. In the pelvis, the basilar portions of the iliac bones may be short and broad with horizontal roofs.
The skeletal changes are qualitatively similar in all patients but vary in expression. They may predominate in the metaphyses or spine.
Spondyloenchondrodysplasia is a genetic disorder with autosomal recessive inheritance. Two brothers from our family had a severe form and their relative a mild form, indicating a marked degree of intrafamilial variability of expression.
The disorder must be differentiated from other spondylometaphyseal dysplasias.72 Most helpful in this respect are the peculiar form of the vertebral bodies and the enchondroma-like lesions of the tubular and flat bones. In their absence the exact diagnosis may be difficult. Diagnosis may be impossible in adulthood when the physes have closed and the vertebral abnormalities are less distinct.
Following the original report,1 most authors include spondyloenchondrodysplasia in the group of enchondromatoses. However, the enchondromatous nature of the skeletal lesions has not as yet been histologically proven.