Sclerosing bone dysplasia

Sclerosing bone dysplasia

Description

Osteosclerosis means increased bone density without expansion of the bone. Hyperostosis implies increased bone density associated with bone expansion. Osteopetrosis (marble bone) also indicates increased bone density but tends to be used for two specific inherited disorders: autosomal dominant and autosomal recessive osteopetrosis.

Diagnosis

Increased bone density is detected postnatally by conventional radiography and in practice is a subjective determination based on apparent radio-density. Densitometry may be performed on bones using radiographs taken under standard conditions. Prenatally accurate density assessment is impossible although a general impression may be obtained. Increased bone density may be generalized, affecting all bones of the membranous and cartilaginous skeleton, or may be localized, only affecting specific bones. Usually only those conditions with generalized increased bone density are diagnosed at or shortly before birth. These disorders are often progressive with bones showing increased density over time as well as associated complications, including bony fragility, anemia and nerve compression. There are numerous conditions described as generalized osteosclerotic bone dysplasias; these include pycnodysostosis, Raine syndrome, sclerosteosis and craniodiaphyseal dysplasia (see sclerosing bone dysplasia associated syndrome listing for further details). Some conditions, including Caffey-Kenny cortical hyperostosis, Melnick-Needles osteodysplasty syndrome and frontometaphyseal dysplasia, are associated with segmental or localized areas of increased bone density and are not generally diagnosed in early life.

Differential Diagnosis

In the lethal form of metatropic dysplasia there is marked long bone shortening as well as mushroom-like widening of the metaphyses which is not found in Raine syndrome. In benign osteosclerosis of the newborn the infant is otherwise normal and the increased bone density seen in fetal and early neonatal life gradually resolves in the first few weeks of life. In osteopetrosis there is poor tubulation of long bones and precocious bone maturation in association with hepatosplenomegaly and disease progression.

Sonographic Features

The following features (if present) may be detectable on prenatal ultrasound Lenz-Majewski syndrome – growth retardation

Syndactyly – disproportionately large head

Hypertelorism

Raine syndrome 

Microcephaly – small for gestational age (length and weight) – bell-shaped chest and pulmonary hypoplasia

Micrognathia

Sclerosteosis – partial/total syndactyly of the fingers, 2/3

Pycnodysostosis

Brachydactyly

Porencephalic cyst

Associated Syndromes

  • Craniodiaphyseal dysplasia
  • Dysosteosclerosis
  • Lenz-Majewski (Braham) hyperostotic dwarfism
  • Pycnodysostosis
  • Raine
  • Sclerosteosis
  • Van Buchem (endosteal hyperostosis)

References

Dudin AA, Rambaud-Cousson A Syndrome of infantile osteopetrosis and Hirschsprung disease in seven children born to four consanguinous unions in two families Am J Med Genet 47:1083-1085
Nishimura G, Kozlowski K Osteosclerotic metaphyseal dysplasia Pediatr Radiol 23:450-452
Chitayat D, Silver K, Azouz EM Skeletal dysplasia, intracerebral calcifications, optic atrophy, hearing impairment, and mental retardation: Nosology of dysosteosclerosis Am J Med Genet 43:517-523
Kan AE, Kozlowski K New distinct lethal osteosclerotic bone dysplasia (Raine syndrome) Am J Med Genet 43:860-864
Ozsoylu S, Besim A Osteosclerosis versus osteopetrosis of the newborn (letter; comment) J Pediatr 118:252-256
Kingston HM, Freeman MB, Hall CM A new lethal sclerosing bone dysplasia Skeletal Radiol 20:117-119
Figueiredo J, Reis A, Vaz R, et al Porencephalic cyst in pycnodysostosis J Med Genet 26:782-784
Raine J, Winter RM, Davey A, et al Unknown syndrome: Microcephaly, hypoplastic nose, exophthalmos, gum hyperplasia, cleft palate, low set ears, and osteosclerosis J Med Genet 26:786-788
Beighton P Syndrome of the month: Sclerosteosis J Med Genet 25:200-203
Gorlin RJ, Whitley CB Lenz-Majewski syndrome Radiology 149:129-131
Robinow M, Johanson AJ, Smith TH The Lenz-Majewski hyperostotic dwarfism: a syndrome of multiple congenital anomalies, mental retardation, and progressive skeletal sclerosis J Pediatr 91:417-421
Lenz WD, Majewski F A generalized disorder of the connective tissues with progeria, choanal atresia, symphalangism, hypoplasia of dentine and craniodiaphyseal hyperostosis Birth Defects OAS 10:133-136