History Page: Leaders in MSK Radiology Brian Joseph Cremin (1929-2012).

This history page in the series "Leaders in MSK Radiology" is dedicated to the achievements of the British radiologist Brian Cremin, one of the pioneers of imaging of skeletal dysplasias.

John P. Caffey, 1895-1978.

This history page in the series "Leaders in MSK Radiology" is dedicated to the achievements of Dr. John Caffey, whose name is associated with infantile cortical hyperostosis, also known as Caffey's disease.

Kazimierz S. Kozlowski, 1928.

This history page in the series "Leaders in MSK Radiology" is dedicated to the achievements of the Polish radiologist Kazimierz Kozlowski, whose name is associated with the Kozlowski type of spondylometaphyseal dysplasia.

Jacques Calvé, 1875-1954.

This history page in the series "Leaders in MSK Radiology" is dedicated to the memory and achievements of the French physician Jacques Calvé, whose name is partially associated with the medical eponym Legg-Calvé-Perthes disease.

Detecting genetic modifiers of spondyloepimetaphyseal dysplasia with joint laxity in the Caucasian Afrikaner community.

Spondyloepimetaphyseal dysplasia with joint laxity (SEMDJL) is an autosomal-recessive skeletal dysplasia. A relatively large number of patients with SEMDJL have been identified in the Caucasian Afrikaans-speaking community in South Africa. We used a combination of Genome-Wide Human Single Nucleotide Polymorphism (SNP) Array 6.0 data and whole exomic data to potentially dissect genetic modifiers associated with SEMDJL in Caucasian Afrikaans-speaking patients. Leveraging the family-based association signal in prioritizing candidate mutations, we identified two potential modifier genes, COL1A2 and MATN1, and replicating previously identified mutation in KIF22. Importantly, our findings of genetic modifier genes and previously identified mutations are layered on the same sub-network implicated in syndromes characterized by skeletal abnormalities and intellectual disability, bone and connective tissue fragility. This study has potentially provided crucial insights in identifying the indirect modifying mutation(s) linked to the true causal mutation associated with SEMDJL. It is a critical lesson that one may use constructively especially when the pace of exomic sequencing of rare disorders continues apace.

The evolution of the nosology of osteogenesis imperfecta.

Osteogenesis imperfecta (OI) is a relatively common genetic skeletal disorder with an estimated frequency of 1 in 20 000 worldwide. The manifestations are diverse and although individually rare, the several different forms contribute to the production of a significant number of affected individuals with considerable morbidity and mortality. During the last decade, there have been extensive molecular investigations into the etiology of OI and these advances have direct relevance to the medical management of the disorder, and the purpose of this review is to document the history and evolution of the nosology of OI. The current nosology, based on molecular concepts, which are crucial in the identification of genotype-phenotype correlations in persons with OI, is also outlined. The successive revisions of the nosology and classification of OI have highlighted the importance of the nomenclature of the condition in order for it to be recognized by clinicians, scientists and patient advocacy groups. In this way, improved counseling of patients and individualized, tailored therapeutic approaches based on the underlying pathophysiology of the individual's type of OI have been facilitated.

Renal dysfunction, rod-cone dystrophy, and sensorineural hearing loss caused by a mutation in RRM2B.

More than two decades ago, a recessive syndromic phenotype affecting kidneys, eyes, and ears, was first described in the endogamous Afrikaner population of South Africa. Using whole-exome sequencing of DNA from two affected siblings (and their carrier parents), we identified the novel RRM2B c.786G>T variant as a plausible disease-causing mutation. The RRM2B gene is involved in mitochondrial integrity, and the observed change was not previously reported in any genomic database. The subsequent screening revealed the variant in two newly presenting unrelated patients, as well as two patients in our registry with rod-cone dystrophy, hearing loss, and Fanconi-type renal disease. All patients with the c.786G>T variant share an identical 1.5 Mb haplotype around this gene, suggesting a founder effect in the Afrikaner population. We present ultrastructural evidence of mitochondrial impairment in one patient, to support our thesis that this RRM2B variant is associated with the renal, ophthalmological, and auditory phenotype.

Novel mutation in the BMPR1B gene (R486L) in a Polish family and further delineation of the phenotypic features of BMPR1B-related brachydactyly.

BACKGROUND: Lehmann et al., [2003, 2006] have documented two different substitutions at position 486 of the BMPR1B gene which resulted in a phenotype of brachydactyly A2 [MIM 112600] or brachydactyly C with symphalangism [MIM 113100]. METHODS: In this article we report a family of Polish extraction with a novel mutation: c.1457G>T (R486L) which segregated with a complex brachydactyly. Clinical and radiological data are presented and details of previously reported patients with a pathogenic change of an amino acid at position 486 of the BMPR1B gene are summarized. CONCLUSION: Our data extends the previously known mutational and radiological spectrum associated with mutations in the BMPR1B gene and confirms the existence of a universal hotspot in the BMPR1B gene in this distinctive autosomal dominant brachydactyly disorder. It is of interest that an affected female in the Polish family had a severe congenital malformation of the venous system in addition to her digital anomalies. This observation raises the possibility of disturbance of embryonic angiogenesis by specific mutations in BMPR1B.

Fibrodysplasia ossificans progressiva in South Africa: difficulties in management in a developing country.

Fibrodysplasia ossificans progressiva is a rare genetic disorder in which progressive ossification of connective tissue leads to severe disability. The condition is an autosomal dominant trait, and most of the affected persons represent new mutations for the determinant gene, ACVR1, chromosomal locus 2q23-24. Although fibrodysplasia ossificans progressiva has a worldwide distribution, there are only a few reports of affected persons of indigenous African stock. We studied and documented 3 affected individuals in the African (Xhosa) community from South Africa. In addition to describing the manifestations and natural history of the disorder in Africa, we discuss the challenge of management of this condition in the South African context.

Taurodontism in dental genetics.

Taurodontism is a dental anomaly defined by enlargement of the pulp chamber of multirooted teeth with apical displacement of the pulp floor and bifurcation of the roots. Taurodontism can be an isolated trait or part of a syndrome. A study was conducted to document the dental and craniofacial aspects of genetic thin bone disorders in South Africa. Sixty-four individuals with Osteogenesis imperfecta (OI), one individual with Pyle disease and one with Torg-Winchester syndrome respectively, were assessed clinically, radiographically and at a molecular level. Ten patients with OI XI and those with Pyle disease and Torg-Winchester syndrome had taurodontism. Taurodontism has been identified in several genetic disorders necessitating cognizance of the possible existence and implications of this characteristic when managing patients in the dental environment. Further studies should be directed toward identifying the incidence, etiology, and molecular pathways leading to taurodontism and its relationship to genetic syndromes.

Arterial rupture in classic Ehlers-Danlos syndrome with COL5A1 mutation.

The vascular type of Ehlers-Danlos syndrome (EDS IV) is associated with a high risk of life-threatening medical complications, including ruptures of large arteries, the intestine, and the uterus during pregnancy. An arterial rupture occurring in an individual with EDS is regarded as almost diagnostic of EDS IV, which is caused by heterozygous mutations in COL3A1. Here however, we report on a man with skin lesions typical of EDS, easy bruising and recurrent inguinal hernias who had a spontaneous rupture of the left common iliac artery at the age of 42 years but in whom we detected no COL3A1 mutation. As he clinically fulfilled the diagnostic criteria for classic EDS (EDS I), we sequenced the major EDS I gene COL5A1 and identified a heterozygous de novo nonsense mutation, c.3184C>T (p.R1062X). As, to the best of our knowledge, this is the first report of a patient with COL5A1 mutation-positive classic EDS and rupture of a large artery, we suggest that arterial rupture might be a rare complication of classic EDS. This finding has potential implications for genetic counseling and molecular genetic testing in Ehlers-Danlos syndrome.

Hereditary bone dysplasia with pathological fractures and nodal osteoarthropathy.

A father and daughter both had multiple pathological fractures and nodal osteoarthropathy. The father, aged 50 years, had at least 20 healed fractures of the axial and appendicular skeleton, sustained by minor trauma over his 50-year lifespan, many of which had been surgically fixed prior to his first presentation to us. Fractures of the clavicles, thoracic cage and long bones of the arms and legs, had healed with malalignment and deformity. Healed fractures were complicated by ankylosis of the cervical vertebrae and both elbows. He also had osteoarthritis of the hands, with exuberant osteophytosis, and profound perceptive deafness. His general health was good, his intellect and facies were normal, and his sclerae were white. The daughter, aged 27 years, had sustained at least seven fractures of the axial and appendicular skeleton following trivial injuries, in distribution similar to those of the father.She had also experienced painful swelling of the fingers,which preceded progressive development of nodal osteoarthropathy.Her hearing was normal. In both individuals,biochemical and immunological investigations yielded normal results. It was not possible for molecular studies to be undertaken. Pedigree data were consistent with autosomal dominant transmission, and this disorder appeared to be a previously undocumented heritable skeletal dysplasia.

Visceral manifestations of hypochondrogenesis.

Autopsy of a stillborn neonate with hypochondrogenesis revealed severe cardiac abnormalities and extensive diverticulosis of the proximal region of the small intestine. Visceral ramifications are unusual in hypochondrogenesis; they may reflect heterogeneity of the intramolecular defect in the COL2A1 gene that codes for the achondrogenesis type II-hypochondrogenesis spectrum of disorders.

Dyssegmental dysplasia in a South African neonate.

A female neonate born to nonconsanguineous Zulu parents had dyssegmental dysplasia, Silverman-Handmaker type. This condition has not previously been reported from the continent of Africa. She died at the age of 4 months following the development of pneumonia complicated by an unexplained anaemia.

Osteogenesis imperfecta and holoprosencephaly.

A 17-week female fetus had severe osteogenesis imperfecta and gross holoprosencephaly. This unusual combination has not previously been documented. No obvious environmental or genetic determinants were present.

Duplication of the nipples and areolae.

A young South African woman has bilateral duplication of the nipples and areolae in an apparently horizontal plane on each breast. She is otherwise normal in every respect, and her family history is negative. This configuration of breast tissue is very unusual and, to the best of our knowledge, it has not previously been reported.

Craniofacial manifestations in osteogenesis imperfecta type III in South Africa.

OBJECTIVES: Osteogenesis imperfecta type III (OMIM 259420) is a severe autosomal recessive disorder. Affected individuals have multiple fractures, develop limb deformities with spinal malalignment and stunted stature. MATERIALS AND METHODS: The frequency of Osteogenesis imperfecta type III (OI III) is relatively high in the indigenous Black African population of South Africa. A review of the literature revealed a paucity of information regarding the craniofacial manifestations of the disorder in this ethnic group. The findings in 64 affected persons are documented. RESULTS: These abnormalities are related to the abnormal bone matrix which results in a deformed skull and dental malocclusion. The physiological process of swallowing may be an aetiological factor in the progressive development of a flattened palate. Mild changes in the shape of the head of the mandibular condyle and a lack of cortical bone on the joint surfaces were observed on cone beam computed tomography (CBCT) images. Affected persons had marked variations in the paranasal sinuses, including sinus hypoplasia and partial opacification. Cranial base anomalies were diagnosed from cephalometric radiographs and lateral skull radiographs. Platybasia and a 'J' shaped sella turcica were observed. CONCLUSION: The craniofacial abnormalities emphasize the importance of a raised level of awareness in terms of dental management and the challenges.

SMD Kozlowski type caused by p.Arg594His substitution in TRPV4 reveals abnormal ossification and notochordal remnants in discs and vertebrae.

Spondylometaphyseal dysplasia Kozlowski type (SMDK) is a monogenic disorder within the TRPV4 dysplasia spectrum and has characteristic spinal and metaphyseal changes. We report skeletal MR imaging in a two-year-old patient who manifested typical clinical and radiographic features of SMDK. The diagnosis was confirmed by molecular analysis which revealed a mutation NM_021625.4:c.1781G > A - p.(Arg594His) in exon 11 of the TRPV4 gene. We have documented abnormalities in endochondral formation of the long and short tubular bones as well as round bones of the wrists and feet. The vertebral bodies had increased thickness of hyaline cartilage which enveloped ossification centers. The vertebrae and discs also had abnormalities in size, shape and structure. These anomalies were most likely the consequence of notochordal remnants presence within the intervertebral discs and in the vertebral bodies. The advantages of MR imaging in bone dysplasias caused by TRPV4 mutations are emphasized in this article.

Osteogenesis imperfecta type 3 in South Africa: Causative mutations in FKBP10.

BACKGROUND: A relatively high frequency of autosomal recessively inherited osteogenesis imperfecta (OI) type 3 (OI-3) is present in the indigenous black southern African population. Affected persons may be severely handicapped as a result of frequent fractures, progressive deformity of the tubular bones and spinal malalignment. OBJECTIVE: To delineate the molecular basis for the condition. METHODS: Molecular investigations were performed on 91 affected persons from seven diverse ethnolinguistic groups in this population. RESULTS: Following polymerase chain reaction amplification and direct cycle sequencing, FKBP10 mutations were identified in 45.1% (41/91) OI-3-affected persons. The homozygous FKBP10 c.831dupC frameshift mutation was confirmed in 35 affected individuals in the study cohort. Haplotype analysis suggests that this mutation is identical among these OI-3-affected persons by descent, thereby confirming that they had a common ancestor. Compound heterozygosity of this founder mutation was observed, in combination with three different deleterious FKBP10 mutations, in six additional persons in the cohort. Four of these individuals had the c.831delC mutation. CONCLUSION: The burden of the disorder, both in frequency and severity, warrants the establishment of a dedicated service for molecular diagnostic confirmation and genetic management of persons and families with OI in southern Africa.