Lung function, diagnosis, and treatment of sleep-disordered breathing in children with achondroplasia.

Children with achondroplasia are at risk of sleep-disordered breathing. The aim of the study was to evaluate lung function and sleep-disordered breathing in children with achondroplasia. An interview, clinical examination, lung function tests with blood gases, and a polygraphic sleep study were obtained as part of routine annual evaluation in consecutive children with achondroplasia. We included 30 children (median age 3.0 years, range: 0.4-17.1) over a period of 21 months. Habitual snoring and witnessed apneas were observed in 77% and 33% of the patients, respectively. Prior to the sleep study, 10/29 (34%) patients had undergone upper airway surgery and 5/29 (17%) craniocervical decompression operation. Arterial blood gases were abnormal in two (7%) patients. Sleep findings were abnormal in 28/30 (93%) patients. Eleven (37%) patients had an apnea index≥1 event/hr and 26 (87%) had an apnea-hypopnea index≥5 events/hr. The ≥3% desaturation index was >5/hr in 22 (73%) patients. Sixteen (53%) patients had a minimal pulse oximetry<90% but only two (7%) patients had a maximal transcutaneous carbon dioxide pressure>50 mmHg during sleep. As a consequence, the following therapeutic interventions were performed: upper airway surgery in four patients and noninvasive positive pressure ventilation (NPPV) in five other patients, resulting in an improvement in sleep studies in all nine patients. Systematic sleep studies are recommended in children with achondroplasia because of the high prevalence of sleep-disordered breathing. Upper airway surgery and NPPV are effective treatments of sleep-disordered breathing.

Oral manifestations of patients with Kenny-Caffey Syndrome.

Kenny-Caffey syndrome (KCS) is a rare osteosclerotic bone dysplasia characterized by hypocalcemia, short stature, ophthalmological features, and teeth anomalies. The TBCE gene coding for a tubulin-specific chaperone E, is located at chromosome 1q42-q43, and is responsible for the recessive form. After reviewing the literature, we found around 60 cases, however with limited dental data. In this article 5 new individuals with KCS, are described focusing on oral findings. All cases had short roots and showed dental anomalies as hypo/oligodontia, microdontia. Dental anomalies are a constant feature in KCS, further study is required to better delineate the syndrome.

Connective tissue nevi: an entity revisited.

BACKGROUND: Connective tissue nevi (CTN) may be isolated, either sporadic or hereditary, or syndromic as in the Buschke-Ollendorff syndrome. Few publications have addressed the variable clinical and histopathologic expression of these benign hamartomas. OBJECTIVE: We sought to characterize the clinical and histopathologic features of CTN and to highlight a spectrum of clinical disease. METHODS: We carried out a retrospective study of cases selected after strict clinical and histopathologic confirmation of the diagnosis. RESULTS: A total of 33 patients with CTN were included. The average age of onset was 2 years. Three clinical forms were distinguished: type A with lesions at a single site, with one case presenting as an ulcerated infiltrated plaque; type B with two or more sites of involvement; and type C with unusually severe infiltration with functional impairment of a limb. Histopathologic examination of lesional biopsy specimens showed 10 collagenomas, one elastoma, 18 mixed CTN, and an increased number of fibroblasts in 4 cases. No correlation between clinical type and histopathologic findings was observed. LIMITATION: This was a descriptive case series. CONCLUSIONS: CTN comprise a clinical spectrum ranging from isolated papules to unusually severe aggressive plaques with monomelic involvement. The histopathologic features are heterogeneous and include a newly described variant, which we name "cellular CTN" because of the increased number of fibroblasts.

Defective chondrocyte proliferation and differentiation in osteochondromas of MHE patients.

Multiple hereditary exostoses (MHE) is an autosomal dominant skeletal disorder caused by mutations in one of the two EXT genes and characterized by multiple osteochondromas that generally arise near the ends of growing long bones. Defective endochondral ossification is likely to be involved in the formation of osteochondromas. In order to investigate potential changes in chondrocyte proliferation and/or differentiation during this process, osteochondroma samples from MHE patients were obtained and used for genetic, morphological, immunohistological, and in situ hybridization studies. The expression patterns of IHH (Indian hedgehog) and FGFR3 (Fibroblast Growth Factor Receptor 3) were similar with transcripts expressed throughout osteochondromas. Expression of PTHR1 (Parathyroid Hormone Receptor 1) transcripts was restricted to a narrow zone of prehypertrophic chondrocytes. Numerous cells forming osteochondromas although resembling prehypertrophic chondrocytes, stained positively with an anti-proliferating cell nuclear antigen (PCNA) antibody. In addition, ectopic expression of collagen type I and abnormal presence of osteocalcin (OC), osteopontin (OP), and bone sialoprotein (BSP) were observed in the cartilaginous osteochondromas. These data indicate that most chondrocytes involved in the growth of osteochondromas can proliferate, and that some of them exhibit bone-forming cell characteristics. We conclude that in MHE, defective heparan sulfate biosynthesis caused by EXT mutations maintains the proliferative capacity of chondrocytes and promotes phenotypic modification to bone-forming cells.

Spondyloenchondrodysplasia with spasticity, cerebral calcifications, and immune dysregulation: clinical and radiographic delineation of a pleiotropic disorder.

Enchondromas are a feature of several constitutional disorders of bone, and the classification of different nosologic entities is still provisional. Among these disorders, spondyloenchondrodysplasia (SPENCD), as outlined by Schorr et al. [1976], is defined by the presence of radiolucent spondylar and metaphyseal lesions that represent persistence of islands of chondroid tissue within bone. Careful review of radiographic findings is needed to distinguish SPENCD from the many other disorders combining enchondromas with spinal lesions. Even when strict criteria are applied, it appears that SPENCD is clinically heterogeneous, as some SPENCD patients are neurologically intact while others present with spasticity, mental retardation, and cerebral calcifications in different combinations, and it has been suggested that SPENCD should be divided in two types. We herein report ten individuals from six families with SPENCD and illustrate the radiographic changes. Seven individuals had CNS manifestations including spasticity, developmental delay, and late-onset cerebral calcifications. We also noted that six individuals had clinical manifestations of autoimmunity (auto-immune thrombocytopenic purpura, auto-immune hemolytic anemia, auto-immune thyroiditis, and SLE) and one had been diagnosed with immune deficiency. Neurological and autoimmune manifestations were seen in different combinations within one single family. These observations suggest that SPENCD may be a single entity defined by specific radiographic features, but with remarkably pleiotropic manifestations that include CNS disease (spasticity, mental retardation, and calcifications), as well as immune dysregulation ranging from autoimmunity to immunodeficiency. The notion of recessive inheritance hitherto assumed is challenged by the observation of two apparently dominant pedigrees.