Expanding the phenotypic spectrum of Caffey disease

Polyostotic cortical hyperostosis in an 8-week-old cat with a 3-year follow-up

A 2 month-old female cat, mixed breed, was referred for difficulty moving and severe enlargement of the mandible and limbs. Polyostotic cortical hyperostosis was diagnosed based on diagnostic imaging and histopathological changes of the mandible and limbs. Marked cortical bone thickening was detected on radiographs and CT scan images. The diaphyses of both radii and ulnae, together with the mandibular rami and bodies, were most severely affected. The many similarities shared with the human condition, Caffey's disease, are discussed.

Molecular mechanisms and clinical manifestations of rare genetic disorders associated with type I collagen

Type I collagen is an important structural protein of bone, skin, tendon, ligament and other connective tissues. It is initially synthesized as a precursor form, procollagen, consisting of two identical pro-α1(I) and one proα2(I) chains, encoded by COL1A1 and COL1A2, respectively. The N- and C- terminal propeptides of procollagen are cleavage by N-proteinase and C-proteinase correspondingly, to form the central triple helix structure with Gly-X-Y repeat units. Mutations of COL1A1 and COL1A2 genes are associated with osteogenesis imperfecta, some types of Ehlers-Danlos syndrome, Caffey diseases, and osteogenesis imperfect/Ehlers- Danlos syndrome overlapping diseases. Clinical symptoms caused by different variations can be variable or similar, mild to lethal, and vice versa. We reviewed the relationship between clinical manifestations and type I collagen - related rare genetic disorders and their possible molecular mechanisms for different mutations and disorders.

Extracellular matrix disruption is an early event in the pathogenesis of skeletal disease in mucopolysaccharidosis I

Progressive skeletal and connective tissue disease represents a significant clinical burden in all of the mucopolysaccharidoses. Despite the introduction of enzyme replacement strategies for many of the mucopolysaccharidoses, symptomatology related to bone and joint disease appears to be recalcitrant to current therapies. In order to address these unmet medical needs a clearer understanding of skeletal and connective tissue disease pathogenesis is required. Historically the pathogenesis of the mucopolysaccharidoses has been assumed to directly relate to progressive storage of glycosaminoglycans. It is now apparent for many lysosomal storage disorders that more complex pathogenic mechanisms underlie patients' clinical symptoms. We have used proteomic and genome wide expression studies in the murine mucopolysaccharidosis I model to identify early pathogenic events occurring in micro-dissected growth plate tissue. Studies were conducted using 3 and 5-week-old mice thus representing a time at which no obvious morphological changes of bone or joints have taken place. An unbiased iTRAQ differential proteomic approach was used to identify candidates followed by validation with multiple reaction monitoring mass spectrometry and immunohistochemistry. These studies reveal significant decreases in six key structural and signaling extracellular matrix proteins; biglycan, fibromodulin, PRELP, type I collagen, lactotransferrin, and SERPINF1. Genome-wide expression studies in embryonic day 13.5 limb cartilage and 5 week growth plate cartilage followed by specific gene candidate qPCR studies in the 5week growth plate identified fourteen significantly deregulated mRNAs (Adamts12, Aspn, Chad, Col2a1, Col9a1, Hapln4, Lum, Matn1, Mmp3, Ogn, Omd, P4ha2, Prelp, and Rab32). The involvement of biglycan, PRELP and fibromodulin; all members of the small leucine repeat proteoglycan family is intriguing, as this protein family is implicated in the pathogenesis of late onset osteoarthritis. Taken as a whole, our data indicates that alteration of the extracellular matrix represents a very early event in the pathogenesis of the mucopolysaccharidoses and implies that biomechanical failure of chondro-osseous tissue may underlie progressive bone and joint disease symptoms. These findings have important therapeutic implications.

Two Japanese familial cases of Caffey disease with and without the common COL1A1 mutation and normal bone density, and review of the literature

Caffey disease, also known as infantile cortical hyperostosis, is a rare bone disease characterized by acute inflammation with swelling of soft tissues and hyperostosis of the outer cortical surface in early infancy. The common heterozygous mutation of the COL1A1 gene, p.Arg1014Cys, has been reported in patients with Caffey disease. However, its pathogenesis remains to be elucidated, and the reason for the incomplete penetrance and transient course of the disease is still unclear. In the present study, we performed mutation analysis of the COL1A1 and COL1A2 genes and measured bone mineral density in two Japanese familial cases of Caffey disease. The index case and two clinically healthy members of one family carry the common heterozygous mutation; in contrast, no mutation in COL1A1 or COL1A2 was identified in the affected members of the second family. In addition, we found normal bone mineral density in adult patients of both families who have had an episode of cortical hyperostosis regardless of the presence or absence of the common p.Arg1014Cys mutation.

CONCLUSION

The results reveal that Caffey disease is genetically heterogeneous and that affected and unaffected adult patients with or without the common COL1A1 mutation have normal bone mineral density.

Caffey disease: new perspectives on old questions

The autosomal dominant form of Caffey disease is a largely self-limiting infantile bone disorder characterized by acute inflammation of soft tissues and localized thickening of the underlying bone cortex. It is caused by a recurrent arginine-to-cysteine substitution (R836C) in the α1(I) chain of type I collagen. However, the functional link between this mutation and the underlying pathogenetic mechanisms still remains elusive. Importantly, it remains to be established as to how a point-mutation in type I collagen leads to a cascade of inflammatory events and spatio-temporally limited hyperostotic bone lesions, and how structural and inflammatory components contribute to the different organ-specific manifestations in Caffey disease. In this review we attempt to shed light on these questions based on the current understanding of other mutations in type I collagen, their role in perturbing collagen biogenesis, and consequent effects on cell-cell and cell-matrix interactions.

Recurrence of infantile cortical hyperostosis: a case report and review of the literature

OBJECTIVE

Also named Caffey disease, infantile cortical hyperostosis is a rare disease that usually affects children of a few weeks of age. The clinical picture is that of irritability, soft tissue swelling at various sites (mandible, clavicle, limbs) with local warmth, and pain on palpation. Radiographs demonstrate an important cortical thickening of the affected bony structures. There is generally spontaneous resolution of the inflammatory signs within the first few months or years of life, without future recurrence. We report the case of a recurrence in the adolescent period and conducted a thorough review of the literature to confirm this rare possibility.

METHODS

We report the case of a 12-year-old female patient, presenting symptoms of pain and swelling of both forearms and legs, similar to her initial clinical picture at 1 month of age when the diagnosis of Caffey disease was made. Genetic analysis confirmed the COL1A1 mutation, the classic mutation described in the familial form of this disease. Radiologic investigation revealed new periosteal bone formation of the right and left ulnae and the left fibula, suggesting a recurrence of cortical hyperostosis. A thorough review of the literature was conducted, using the Medline database between 1948 and 2011, to confirm this hypothesis.

RESULTS

The literature confirms the possibility but also the rarity of a recurrence of cortical hyperostosis in an adolescent who was diagnosed with Caffey disease in infancy. We have identified less than a dozen cases in the literature describing such a recurrence and in the majority there are no medical photographs or radiographs to support the clinical diagnosis. Our case is well documented both clinically and radiologically regarding the initial presentation and the recurrence in adolescence.

CONCLUSIONS

Although very rare and poorly recognized, the diagnosis of recurrent cortical hyperostosis must be evoked in a patient who suffered from Caffey disease in infancy, and presents similar clinical characteristics in the adolescent period.

LEVEL OF EVIDENCE

Level V--case report.

COL1A1 mutation in an Indian child with Caffey disease

Caffey disease or infantile cortical hyperostosis is a rare skeletal disorder with both sporadic and familial occurrence. The autosomal dominant familial form has been found to be a collagenopathy. The case being reported is a 7- month-old Indian boy with Caffey disease who was found to have the R1014C heterozygous mutation in the COL1A1 gene. This is the first mutation report of an Indian case with Caffey disease.

Juvenile mandibular chronic osteomyelitis: multimodality imaging findings

BACKGROUND AND PURPOSE

Juvenile mandibular chronic osteomyelitis is a rare entity that predominantly affects children and adolescents, but little is known about the factors that contribute to the recurrent course and eventual resolution of this disease. Here, we describe new findings of soft tissue and mandibular nerve canal involvement.

MATERIALS AND METHODS

Four patients with mandibular diffuse sclerosing osteomyelitis are presented; all were followed with CT, a few also with MRI and bone scan. We recorded imaging findings of lesion location, pattern of bone formation, presence and evolution of lytic lesions, mandibular nerve, and soft tissue involvement.

RESULTS

In all patients we found enlargement of the mandibular nerve canal and soft tissue changes on CT and MRI (when available). All patients had ground glass bone patterns in conjunction with lamellated/onion skin new periosteal bone formation on CT, and all patients with follow-up CT had change in lytic lesion locations.

CONCLUSION

Mandibular nerve canal enlargement, soft tissue abnormalities, and change in location of lytic lesions may represent a diagnostic pattern in mandibular diffuse sclerosing osteomyelitis (Garré) that was not previously entirely recognized as such.

New perspectives on osteogenesis imperfecta

A new paradigm has emerged for osteogenesis imperfecta as a collagen-related disorder. The more prevalent autosomal dominant forms of osteogenesis imperfecta are caused by primary defects in type I collagen, whereas autosomal recessive forms are caused by deficiency of proteins which interact with type I procollagen for post-translational modification and/or folding. Factors that contribute to the mechanism of dominant osteogenesis imperfecta include intracellular stress, disruption of interactions between collagen and noncollagenous proteins, compromised matrix structure, abnormal cell-cell and cell-matrix interactions and tissue mineralization. Recessive osteogenesis imperfecta is caused by deficiency of any of the three components of the collagen prolyl 3-hydroxylation complex. Absence of 3-hydroxylation is associated with increased modification of the collagen helix, consistent with delayed collagen folding. Other causes of recessive osteogenesis imperfecta include deficiency of the collagen chaperones FKBP10 or Serpin H1. Murine models are crucial to uncovering the common pathways in dominant and recessive osteogenesis imperfecta bone dysplasia. Clinical management of osteogenesis imperfecta is multidisciplinary, encompassing substantial progress in physical rehabilitation and surgical procedures, management of hearing, dental and pulmonary abnormalities, as well as drugs, such as bisphosphonates and recombinant human growth hormone. Novel treatments using cell therapy or new drug regimens hold promise for the future.

Infantile cortical hyperostosis and COL1A1 mutation in four generations

Infantile cortical hyperostosis (ICH, OMIM 114000) is a rare familial disorder which affects infants. It spontaneously heals in the first years of life. The disease is characterized by regressive subperiosteal hyperosteogenesis mainly affecting long bones, mandible, clavicles, and ribs which are remarkably swollen and deformed on X-rays. But it is also important to take into consideration the autosomal dominant pattern of inheritance to detect it. In 2005 Gensure et al. detected 3040C → T mutation in COL1A1 gene in three unrelated ICH families. Four generations of patients belonging to the same family were examined in our study. Molecular testing has now disclosed a pathogenic mutation in nine of them. The patients spontaneously recovered. Although our paper shows a distinct correlation between R836C mutation and ICH, there is a certain interindividual and intra-familial variability.

The c.3040C > T mutation in COL1A1 is recurrent in Korean patients with infantile cortical hyperostosis (Caffey disease)

Infantile cortical hyperostosis (ICH) is characterized by spontaneous episodes of subperiosteal new bone formation in the long bones, mandible, and clavicle during infancy. A heterozygous missense mutation, c.3040C > T (p.R1014C), in the type I collagen alpha1 chain gene (COL1A1) was reported in families with the autosomal dominant form of ICH. We examined six consecutive cases of ICH from five unrelated families and their parents. The mutation was identified in all patients and two parents tested. Our result supported that ICH is caused by the single mutation in COL1A1 with incomplete penetrance.