All laboratory investigations including
karyotype, metabolic screening, and studies of cholesterol biosynthesis and
peroxisomes yielded normal results, and the underlying defect has not been
identified. However, the features of the disease suggest that a collagen
gene defect is involved. Clinical signs may involve the head and neck
(microcephaly, overfolded ears with dysplastic helices, flat nose with
vertically grooved nasal tip, short philtrum, abnormal enamel projections,
gingiva hypertrophy), the central nervous system (developmental delay), the
eyes (congenital cataracts, ptosis, nystagmus), the skeleton (delayed
ossification of upper and lower extremities, odontoid hypoplasia, deformed
vertebral bodies with coronal clefts, scoliosis, radiologic signs of
spondyloepiphyseal dysplasia, generalized abnormalities of the ilium, joint
dislocations, hypoplastic pectoral muscles, generalized hypotonia,
restricted pronation and supination), and the skin (alopecia).