Hereditary Multiple Exostoses, A Tale of 50 years

An unusual example of hereditary multiple exostoses: a case report and review of the literature

Background

Hereditary multiple exostoses (HME) is a rare skeletal disorder characterised by a widespread.

distribution of osteochondromas originating from the metaphyses of long bones.

Case presentation

This case study examines a 55-year-old male cadaver bequeathed to the University of Liverpool who suffered from HME, thus providing an exceptionally rare opportunity to examine the anatomical changes associated with this condition.

Conclusions

Findings from imaging and dissection indicated that this was a severe case of HME in terms of the quantity and distribution of the osteochondromas and the number of synostoses present. In addition, the existence of enchondromas and the appearance of gaps within the trabeculae of affected bones make this a remarkable case. This study provides a comprehensive overview of the morbidity of the disease as well as adding to the growing evidence that diseases concerning benign cartilaginous tumours may be part of a spectrum rather than distinct entities.

Brachymetacarpia and Brachymetatarsia in Patients with Multiple Hereditary Exostosis

Background

Multiple hereditary exostosis is a common autosomal dominant inherited musculoskeletal disorder that manifests with multiple osteochondromas. The clinical manifestations and pathological characteristics of osteochondromas found in the long bone and genetic alterations related to multiple hereditary exostosis have been widely reported. In this study, we investigated the characteristics of brachymetacarpia and brachymetatarsia associated with multiple hereditary exostosis.

Methods

Of the 133 patients with a diagnosis of multiple hereditary exostosis who were recruited from 2005 to 2018, 101 patients who underwent plain radiography after 10 years of age were included. There were 55 male (54.5%) and 46 female (45.5%) patients. Brachymetacarpia or brachymetatarsia was diagnosed when disruption of the Lièvre parabola connecting the metacarpal or metatarsal heads was observed on plain radiographs. Three orthopedic surgeons individually reviewed hand and foot plain radiographs.

Results

Of the 101 patients, 41 patients (40.6%) had more than 1 brachymetacarpia (88 cases) or brachymetatarsia (81 cases). Among 41 cases, 22 (53.7%) were male and 19 (46.3%) were female. The mean age at the time of radiographic evaluation of the hands and feet was 14.6 years (range, 10–63 years). Shortening was most commonly found in the 3rd and 4th metacarpal or metatarsal bones.

Conclusions

We found a relatively high incidence of brachymetacarpia and brachymetatarsia in our patients. Physicians should suspect the presence of brachymetacarpia and brachymetatarsia when treating patients with multiple hereditary exostosis.

A review of skeletal dysplasia research in India

We aimed to review the contributions by Indian researchers to the subspecialty of skeletal dysplasias (SDs). Literature search using specific keywords in PubMed was performed to retrieve all the published literature on SDs as on July 6, 2017. All published literature on SDs wherein at least one author was from an Indian institute was included. Publications were grouped into different categories based on the major emphasis of the research paper. Five hundred and forty publications in English language were retrieved and categorized into five different groups. The publications were categorized as reports based on: (i) phenotypes (n = 437), (ii) mutations (n = 51), (iii) novel genes (n = 9), (iv) therapeutic interventions (n = 31), and (v) reviews (n = 12). Most of the publications were single-patient case reports describing the clinical and radiological features of the patients affected with SDs (n = 352). We enlisted all the significant Indian contributions. We have also highlighted the reports in which Indians have contributed to discovery of new genes and phenotypes. This review highlights the substantial Indian contributions to SD research, which is poised to reach even greater heights given the size and structure of our population, technological advances, and expanding national and international collaborations.

Heterogeneous spectrum of EXT gene mutations in Chinese patients with hereditary multiple osteochondromas

Hereditary multiple osteochondroma (HMO) is one of the most common genetic skeletal disorders. It is caused by mutations in either EXT1 or EXT2 resulting in abnormal skeletal growth and morphogenesis. However, the spectrum and frequency of EXT1 and EXT2 mutations in Chinese patients with HMO was not previously investigated.Mutations were identified by performing Sanger sequencing analysis of the complete coding regions and flanking intronic sequences of EXT1 and EXT2, followed by multiplex ligation-dependent probe amplification (MLPA) analysis to detect gene deletions or duplications that could not be identified by the Sanger sequencing method.The present study identified pathogenic mutations in 93% (68/73) of unrelated HMO probands from 73 pedigrees. Mutations in EXT1 and EXT2 were identified in 53% (39/73) and 40% (29/73) of families. We identified 58 distinct mutations in EXT1 and EXT2, including 20 frameshift mutations, 16 nonsense mutations, 7 missense mutations, 9 splice site mutations, 5 large deletions, and 1 in-frame deletion mutation. Twenty-six of these mutations were novel and 32 were previously reported. Most of the mutations in EXT1 were base deletions or insertions (21/33), whereas the majority of those in EXT2 were single base substitution (18/25).Complete sequencing of both the EXT1 and EXT2 followed by MLPA analysis is recommended for genetic analysis of Chinese patients with HMO. This study provides a comprehensive characterization of the genetic aberrations found in Chinese patients with HMO and highlights the diagnostic value of molecular genetic analysis in this particular disease.

The impact of hereditary multiple exostoses on quality of life, satisfaction, global health status, and pain

PURPOSE

The aim of the study was to evaluate quality of life (QOL), global health status, pain, and level of satisfaction in patients with hereditary multiple exostoses (HME), and to correlate the association between the severity of diseases and age, sex, number of surgical procedures, and number of exostoses.

METHODS

The data of 50 patients with HME were retrospectively evaluated and recorded. QOL was evaluated with the Short-Form Health Survey (SF-12) questionnaire, the 12-Item General Health Questionnaire (GHQ-12), and Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q-SF); intensity of pain was measured using the visual analogue scale (VAS). The association of age, gender, pain, quality of life, number of exostoses, and number of surgical procedures were evaluated and correlated.

RESULTS

Mean number of exostoses in our patient's cohort resulted 18.12 ± 8.60, and every patient underwent to a mean of 5.62 ± 5.74 surgical procedures for the exostoses. Mean VAS resulted 5.16 ± 2.90. Considering SF-12, mental (MCS) and physical (PCS) component resulted, respectively, 45.36 ± 10.76 and 38.73 ± 11.09, while GHQ-12 and Q-LES-Q-SF were 15.48 ± 4.70 and 45.28 ± 9.55, respectively. We found a significant positive correlation between the number of exostoses and the number of surgical procedures (p < 0.001), a significant positive correlation between the number of surgical procedures and GHQ-12 (p = 0.422) and VAS (p = 0.0011), and a negative correlation between the number of surgical procedures and PCS (p = 0.0257) and between age and GHQ-12 (p = 0.0385).

CONCLUSIONS

We can conclude that HME impact on patient quality of life as measured by the MCS and PCS scores similar to the disability associated with osteoarthritis in the mental component and tumors or diabetes as regards the physical component. Moreover, we found no difference in patients' quality of life as regards number of exostoses, age, and surgical procedure, but we found that women have a worse response as regards the psychological side than men.