Multiple epiphyseal dysplasia

Testing the Digital Atlas of Ancient Rare Diseases (DAARD) using a new case of Legg-Calvé-Perthes disease from Early Byzantine (500-700 CE) Olympia, Greece

OBJECTIVE

The first case of Legg-Calvé-Perthes disease (LCPD) in Greece is presented. LCPD, a rare disease, is discussed using the Digital Atlas of Ancient Rare Diseases (DAARD), which tests the benefits of the database for diagnosing and contextualizing the new case with 42 archaeological cases of LCPD recorded in the DAARD.

MATERIALS

A 30-40-year-old, probable male individual was found at the archaeological site of Olympia, Greece, dating to 500-700 CE.

METHODS

Biological sex, age-at-death and pathological changes were investigated using macroscopic and osteometric methods. The DAARD provided the typical characteristics of LCPD.

RESULTS

Pathological changes in both hip joints without any other related changes in the skeleton corresponded to the skeletal features of LCPD. The DAARD produced 42 cases of LCPD, most of which from Europe, with a preference for male sex and unilateral involvement of the hip joint.

CONCLUSIONS

The DAARD aids in diagnosing rare diseases and interpreting new cases in the context of already known studies.

SIGNIFICANCE

This study shows that the DAARD has the potential to help researchers move beyond the level of single case studies and create a broader picture of the history of rare diseases.

LIMITATIONS

This paper focuses on the benefits of the DAARD in relation to LCPD but not all rare diseases have been included in the database.

SUGGESTIONS FOR FURTHER RESEARCH

More rare diseases from archaeological contexts should be added to the DAARD to create a base for the interpretation of their history and expand our understanding of rare diseases in the past.

Multiple Epiphyseal Dysplasia With Knee Joint Locking Symptoms Caused by Intra-articular Loose Bodies

Multiple epiphyseal dysplasia (MED) is a congenital disease causing epiphyseal dysplasia in long bones. Herein, we report a case of a middle-aged man with bilateral knee joint locking symptoms who was diagnosed with multiple epiphyseal dysplasia caused by Matrilin-3 (MATN3) pathogenic variants and was successfully treated with arthroscopic loose body removal. A 48-year-old man has had bilateral knee pain since his twenties and underwent loose body removal of both knees in his thirties. He visited our hospital for worsening locking symptoms in both knees. Twenty years ago, his son had been diagnosed with suspected multiple epiphyseal dysplasia. Genetic and imaging testing confirmed his diagnosis of multiple epiphyseal dysplasia due to Matrilin-3 pathogenic variants. Arthroscopic loose body removal was performed, and the locking symptoms disappeared after surgery. Arthroscopic loose body removal was effective for the locking symptoms in a mild adult case of multiple epiphyseal dysplasias caused by Matrilin-3 pathogenic variants.

Characteristics of Scoliosis in Mice Induced by Chondrocyte-specific Inactivation of L-type Amino Acid Transporter 1

STUDY DESIGN

A mouse study of the Slc7a5 gene using conditional knockout to assess the effects of its inactivation on spinal deformity.

OBJECTIVES

This study aimed to investigate whether the mice with scoliosis [induced by chondrocyte-specific inactivation of L-type amino acid transporter 1 (LAT1)] show a developmental process similar to that of pediatric scoliosis and to examine the relationship between reduced bone mineral density (BMD) and scoliosis. Furthermore, we aimed to obtain insights into elucidating the etiology and pathophysiology of scoliosis.

SUMMARY OF BACKGROUND DATA

The etiology and pathogenesis of scoliosis are not fully understood despite substantial investigative efforts. LAT1 is an amino acid transporter that mediates the cellular uptake of large neutral amino acids. A recent study revealed that chondrocyte-specific inactivation of LAT1 in mice results in scoliosis (Col2a1-Cre;Slc7a5fl/fl mice: "Sko mice").

MATERIALS AND METHODS

Body length, body weight, Cobb angle, vertebral body rotation angle, and BMD at 1, 2, 4, 6, and 8 weeks of age were examined and statistically compared with those of normal control mice. Pathologic and morphologic evaluation was performed on specimens from 10-week-old euthanized mice.

RESULTS

The Sko mice developed thoracic scoliosis in infancy without congenital malformations. This spinal deformity progressed rapidly during growth, with diverse curve patterns and hypoplastic vertebral bodies. Pathologic examination revealed thickening of the growth plates and decreased osteoblasts, suggesting that impaired endochondral ossification was the cause of the scoliosis. Sko mice were also observed to have decreased BMD and degraded bone microstructure. Reduced BMD and bone quality may not be the causes of the onset and progression of scoliosis in the Sko mice.

CONCLUSIONS

In Sko mice, the characteristics of scoliosis and vertebral pathology showed many similarities with syndromic scoliosis in humans. Endochondral ossification defects may impair growth, leading to scoliosis and decreased BMD.

The favorable outcome of Bernese periacetabular osteotomy for the hip osteoarthritis in multiple epiphyseal dysplasia

BACKGROUND

Multiple epiphyseal dysplasia (MED) is a rare congenital bone dysplasia. Patients with MED develop secondary hip osteoarthritis as early as the third to the fourth decade. Currently, there is no consensus on the prevention of the progressive hip osteoarthritis secondary to MED. The Bernese periacetabular osteotomy (PAO) is a joint-preserving surgery to reshape acetabulum and extend femoral head coverage. However, there is no documentary evidence for the effect of the procedure on MED hips.

PATIENTS AND METHODS

We analyzed the preliminary outcomes following the Bernese PAO in 6 MED hips. The average age at the time of surgery was 14.3 years (range from 11.4 to 17.2 years). For our study interest of time efficiency, radiographic parameters were analyzed preoperatively and 1 year postoperatively. The hip function was evaluated by the Harris Hip Score (HHS) before and after surgery.

RESULTS

The mean follow-up time was 1.7 years. The mean lateral center-edge angle increased from 3.8° to 47.1° (p = 0.02), anterior center-edge angle increased from 7.3° to 35.1° (p = 0.02), and acetabulum index decreased from 27.8° to 14.6° (p = 0.04). The femoral head coverage ratio increased from 66.8% to 100% (p = 0.02). The post-operative anteroposterior pelvic radiograph demonstrated all preoperative broken Shenton lines were reversed. The mean HHS improved from 67.3 to 86.7 (p = 0.05).

CONCLUSION

Bernese PAO is a feasible treatment for hip disorders in MED patients. It reshapes acetabular and femoral morphology efficiently. In our study, the preliminary results showed the procedure not only improved radiographic outcomes but also hip function.

Multiple epiphyseal dysplasia tip 5: Case report a rare skeletal dysplasıa presenting with repetitive joint pain in children

INTRODUCTION AND IMPORTANCE

Multiple epiphyseal dysplasia, which affects the epiphysis of long bones, can show autosomal dominant and autosomal recessive inheritance patterns (Ballhausen et al., 2003 [1]). The symptoms typically appear in childhood, although they sometimes do not show symptoms until adulthood. The goals of treatment in children are to prevent the early onset of osteoarthritis, improve function, and educate patients and their families about the natural history and genetic basis of the disease. Some patients present to the clinic with only non-healing and unidentified joint pain. Although multiple epiphyseal dysplasia type 5 is a rare disease with autosomal dominant inheritance in general, it can also be observed with de novo mutation, although very rarely, without a family history.

CASE PRESENTATION

7-years-old male patient was admitted to our orthopedics outpatient clinic with complaints of joint pain, fatigue, and pain in the knees and ankles that had lasted for about 3 years. He had epicanthus, left hemifacial microsomia, and metacarpophalangeal joint laxity. The arm was proportional to the body. In the laboratory, there was no obvious finding other than vitamin D deficiency. The epiphyses, especially in the ankle, were dysplasic on Xray. After genetic tests we detected multiple epiphyseal dysplasia type 5, with de novo mutation, without family histories.

CLINICAL DISCUSSION

Multiple epiphyseal dysplasia type 5, which is usually an autosomal dominant disease (Ballhausen et al., 2003 [1]) characterized by normal height; it is seen due to heterozygous mutation of matrilin-3 gene (MATN3) at 2p24.1 location. Early-onset osteoarthritis, multiple epiphyseal dysplasia, arthralgia, small proximal femoral epiphyses, wide and short femoral neck, coxa vara, high greater trochanter, small, irregular epiphyses (distal femoral, proximal tibia, distal radius, distal ulna), mild metaphyseal irregularities (distal femoral, proximal tibia, proximal humeri, distal radius, distal ulna), genu valgum may accompany. In hands; small, irregular epiphyses (first metacarpal), delayed carpal ossification may be seen. Delayed tarsal ossification can be observed in the feet. On the other hand, some patients present to the clinic with only non-healing and unidentified joint pain. Although multiple epiphyseal dysplasia type 5 a rare disease with autosomal dominant inheritance in general, it can also be observed like our case with de novo mutation, although very rarely, without a family history.

CONCLUSION

Multiple epiphyseal dysplasia type 5 is a rare disease. It should be kept in mind that skeletal dysplasia should also be evaluated, although it is rarely seen in patients with persistent joint pain. Thus, we can both slow down the progression with early diagnosis of the patient and minimize the early surgical requirements.

Treatment outcomes of hips in patients with epiphyseal dysplasia

Hip containment surgeries in multiple epiphyseal and spondyloepiphyseal dysplasia (MED/SED) patients aim to improve the mechanical environment of the hip joint. The purpose of this study was to determine if surgical intervention to improve femoral head coverage improved radiographic and clinical outcomes. A retrospective study identified patients with MED/SED seen in clinic between May 2000 and September 2017, with a minimum of 2-year follow-up. Patient charts/radiographs were reviewed for radiographic hip measurements, pain, and gait. Sixty-nine hips in 35 patients were identified. Forty-four hips were treated nonoperatively and 25 were treated surgically. The mean age at diagnosis was 6.2 years. The mean follow-up was 7.7 years for the surgical group and 7.1 years for the nonsurgical group. The mean postoperative follow-up was 5.4 years. Acetabular index decreased from initial to final visit by 9.0° in the surgical group and 1.6° in the nonsurgical group. Tonnis angle decreased by 13.5° in the surgical group and 1.5° in the nonsurgical group. Center edge angle increased by 19.0° in the surgical group and 7.1° in the nonsurgical group. Hips in the surgical group were 6.1 times more likely to experience an improvement in pain compared with hips in the nonsurgical group. Gait at the final follow-up was similar among the two groups. In this study cohort, containment surgery provided increased femoral head coverage; however, there was equal femoral head deformation despite intervention. Hips treated surgically were more likely to experience an improvement in pain; however, gait alterations did not improve.

Clinical, Biochemical, Radiological, Genetic and Therapeutic Analysis of Patients with COMP Gene Variants

Pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia type 1 (MED1) are two rare skeletal disorders caused by cartilage oligomeric matrix protein (COMP) variants. This study aims to analyze the genotype and phenotype of patients with COMP variants. Clinical information for 14 probands was collected; DNA was extracted from blood for COMP variant detection. Clinical manifestations and radiology scoring systems were established to evaluate the severity of each patient's condition. Serum COMP levels in PSACH patients and healthy subjects were measured. Thirty-nine patients were included, along with 12 PSACH probands and two MED1 probands. Disproportionate short stature, waddling gait, early-onset osteoarthritis and skeletal deformities were the most common features. The height Z-score of PSACH patients correlated negatively with age at evaluation (r =  - 0.603, p = 0.01) and the clinical manifestation score (r =  - 0.556, p = 0.039). Over 50% of the PSACH patients were overweight/obese. The median serum COMP level in PSACH patients was 16.75 ng/ml, which was significantly lower than that in healthy controls (98.53 ng/ml; p < 0.001). The condition of MED1 patients was better than that of PSACH patients. Four novel variants of COMP were detected: c.874T>C, c.1123_1134del, c.1531G>A, and c.1576G>T. Height Z-scores and serum COMP levels were significantly lower in patients carrying mutations located in calmodulin-like domains 6, 7, and 8. As the two phenotypes overlap to different degrees, PSACH and MED1 are suggested to combine to produce "spondyloepiphyseal dysplasia, COMP type". Clinical manifestations and radiology scoring systems, serum COMP levels and genotype are important for evaluating patient condition severity.

Orthopedic concerns of a child with short stature

PURPOSE OF REVIEW

Pediatric short stature poses severe concerns to the patient, parents, and physicians. Management for pediatric short stature is still widely debated due to heterogenous etiological factors and treatment options. This review will address the approach to pediatric short stature, commonly within the subset of skeletal dysplasia resulting in disproportionate short stature. The following will be discussed: the etiology, clinical, and radiological evaluations, and management for pediatric short stature.

RECENT FINDINGS

Early recognition of short stature and appropriate referrals is shown to benefit the patient and reduce parental concern. A multidisciplinary team, comprising an orthopedic surgeon, is fundamental to provide holistic care and ensure overall good quality of life. Advancements in clinical diagnostic tools and diversified treatment modalities today provides optimism in managing pediatric short stature.

SUMMARY

Skeletal dysplasia can be treated with good prognosis if diagnosed and managed early. Thorough clinical, radiological, laboratory, and even genetic investigations are important to differentiate and manage various types of skeletal dysplasia. Our review will provide a comprehensive and up-to-date approach to skeletal dysplasia for pediatric orthopedic surgeons, and indications for physicians to refer patients with suspected short stature to pediatric orthopedic surgeons.

Compendium of causative genes and their encoded proteins for common monogenic disorders

A compendium is presented of inherited monogenic disorders that have a prevalence of >1:20,000 in the human population, along with their causative genes and encoded proteins. "Simple" monogenic diseases are those for which the clinical features are caused by mutations impacting a single gene, usually in a manner that alters the sequence of the encoded protein. Of course, for a given "monogenic disorder", there is sometimes more than one potential disease gene, mutations in any one of which is sufficient to cause phenotypes of that disorder. Disease-causing mutations for monogenic disorders are usually passed on from generation to generation in a Mendelian fashion, and originate from spontaneous (de novo) germline founder mutations. In the past monogenic disorders have often been written off as targets for drug discovery because they sometimes are assumed to be rare disorders, for which the meager projected financial payoff of drug discovery and development has discouraged investment. However, not all monogenic diseases are rare. Here, we report that that currently available data identifies 72 disorders with a prevalence of at least 1 in 20,000 humans. For each, we tabulate the gene(s) for which mutations cause the spectrum of phenotypes associated with that disorder. We also identify the gene and protein that most commonly causes each disease. 34 of these disorders are caused exclusively by mutations in only a single gene and encoded protein.

Health-related Quality of Life in Adult Patients with Multiple Epiphyseal Dysplasia and Spondyloepiphyseal Dysplasia

Objectives:

Multiple epiphyseal dysplasia (MED) and spondyloepiphyseal dysplasia (SED) are skeletal dysplasias associated with premature osteoarthritis and short stature. Patients with SED often have spinal and ocular problems. Few reports have focused on the health-related quality of life (HRQoL) of patients with skeletal dysplasias associated with premature osteoarthritis. The purpose of this study was to evaluate the HRQoL of adult patients with MED and SED.

Methods:

Questionnaires covering demographics, medical history (cataract, retinal detachment, and osteoarthritis), surgical history (osteotomy and arthroplasty), and the Short Form-36 (SF-36) health survey were sent to all patients with MED and SED with medical records at the investigators’ institutions. Among the 27 patients who completed the questionnaire, patients aged 20 years or older were included in this cohort.

Results:

The subjects were 18 affected individuals. The physical component summary score (PCS) was significantly lower in the MED and SED groups than in the normal population and tended to deteriorate with age. Conversely, there was a positive correlation between the mental component summary score and age. The role/social component summary score was not correlated with age. MED patients with osteoarthritis had a low PCS. PCS was particularly low in two SED patients with a medical history of cataract, whereas there was no association with a history of retinal detachment or osteoarthritis.

Conclusions:

The physical domain of HRQoL in MED and SED patients significantly deteriorated at a young age. Appropriate medical management of these skeletal dysplasias is required not only for orthopedic functions but also for ocular problems.

Massager-Induced Anterior Subcapsular Cataracts and Keratoconus in a Patient With Multiple Epiphyseal Dysplasia

Multiple epiphyseal dysplasia (MED) is a phenotypically heterogeneous disease associated with orthopedic abnormalities among other systemic manifestations. While the spectrum of ocular abnormalities in this disorder is yet to be fully reported, MED has been rarely associated in the literature with the development of cataracts and keratoconus. Here, we report a case of bilateral massager-induced anterior subcapsular cataracts and keratoconus in a 46-year-old female with MED. This case presentation aims to prevent similar occurrences of inappropriate massaging device use and highlight potential ocular findings in MED patients.

Basic Components of Connective Tissues and Extracellular Matrix: Fibronectin, Fibrinogen, Laminin, Elastin, Fibrillins, Fibulins, Matrilins, Tenascins and Thrombospondins

Collagens are the most abundant components of the extracellular matrix (ECM) and many types of soft tissues. Elastin is another major component of certain soft tissues, such as arterial walls and ligaments. It is an insoluble polymer of the monomeric soluble precursor tropoelastin, and the main component of elastic fibers in matrix tissue where it provides elastic recoil and resilience to a variety of connective tissues, e.g., aorta and ligaments. Elastic fibers regulate activity of transforming growth factors β (TGFβ) through their association with fibrillin microfibrils. Elastin also plays a role in cell adhesion, cell migration, and has the ability to participate in cell signaling. Mutations in the elastin gene lead to cutis laxa. Many other molecules, though lower in quantity, function as essential, structural and/or functional components of the extracellular matrix in soft tissues. Some of these are reviewed in this chapter. Besides their basic structure, biochemistry and physiology, their roles in disorders of soft tissues are discussed only briefly as most chapters in this volume deal with relevant individual compounds. Fibronectin with its multidomain structure plays a role of "master organizer" in matrix assembly as it forms a bridge between cell surface receptors, e.g., integrins, and compounds such collagen, proteoglycans and other focal adhesion molecules. It also plays an essential role in the assembly of fibrillin-1 into a structured network. Though the primary role of fibrinogen is in clot formation, after conversion to fibrin by thrombin it also binds to a variety of compounds, particularly to various growth factors, and as such, fibrinogen is a player in cardiovascular and extracellular matrix physiology. Laminins contribute to the structure of the ECM and modulate cellular functions such as adhesion, differentiation, migration, stability of phenotype, and resistance towards apoptosis. Fibrillins represent the predominant core of microfibrils in elastic as well as non-elastic extracellular matrixes, and interact closely with tropoelastin and integrins. Not only do microfibrils provide structural integrity of specific organ systems, but they also provide basis for elastogenesis in elastic tissues. Fibrillin is important for the assembly of elastin into elastic fibers. Mutations in the fibrillin-1 gene are closely associated with Marfan syndrome. Latent TGFβ binding proteins (LTBPs) are included here as their structure is similar to fibrillins. Several categories of ECM components described after fibrillins are sub-classified as matricellular proteins, i.e., they are secreted into ECM, but do not provide structure. Rather they interact with cell membrane receptors, collagens, proteases, hormones and growth factors, communicating and directing cell-ECM traffic. Fibulins are tightly connected with basement membranes, elastic fibers and other components of extracellular matrix and participate in formation of elastic fibers. Matrilins have been emerging as a new group of supporting actors, and their role in connective tissue physiology and pathophysiology has not been fully characterized. Tenascins are ECM polymorphic glycoproteins found in many connective tissues in the body. Their expression is regulated by mechanical stress both during development and in adulthood. Tenascins mediate both inflammatory and fibrotic processes to enable effective tissue repair and play roles in pathogenesis of Ehlers-Danlos, heart disease, and regeneration and recovery of musculo-tendinous tissue. One of the roles of thrombospondin 1 is activation of TGFβ. Increased expression of thrombospondin and TGFβ activity was observed in fibrotic skin disorders such as keloids and scleroderma. Cartilage oligomeric matrix protein (COMP) or thrombospondin-5 is primarily present in the cartilage. High levels of COMP are present in fibrotic scars and systemic sclerosis of the skin, and in tendon, especially with physical activity, loading and post-injury. It plays a role in vascular wall remodeling and has been found in atherosclerotic plaques as well.

"Lessons from Rare Forms of Osteoarthritis"

Osteoarthritis (OA) is one of the most prevalent conditions in the world, particularly in the developed world with a significant increase in cases and their predicted impact as we move through the twenty-first century and this will be exacerbated by the covid pandemic. The degeneration of cartilage and bone as part of this condition is becoming better understood but there are still significant challenges in painting a complete picture to recognise all aspects of the condition and what treatment(s) are most appropriate in individual causes. OA encompasses many different types and this causes some of the challenges in fully understanding the condition. There have been examples through history where much has been learnt about common disease(s) from the study of rare or extreme phenotypes, particularly where Mendelian disorders are involved. The often early onset of symptoms combined with the rapid and aggressive pathogenesis of these diseases and their predictable outcomes give an often-under-explored resource. It is these "rarer forms of disease" that William Harvey referred to that offer novel insights into more common conditions through their more extreme presentations. In the case of OA, GWAS analyses demonstrate the multiple genes that are implicated in OA in the general population. In some of these rarer forms, single defective genes are responsible. The extreme phenotypes seen in conditions such as Camptodactyly Arthropathy-Coxa Vara-pericarditis Syndrome, Chondrodysplasias and Alkaptonuria all present potential opportunities for greater understanding of disease pathogenesis, novel therapeutic interventions and diagnostic imaging. This review examines some of the rarer presenting forms of OA and linked conditions, some of the novel discoveries made whilst studying them, and findings on imaging and treatment strategies.

Paleopathological diagnosis of a proportionate short stature on a female skeleton from the Coimbra collection: Turner syndrome versus other causes

OBJECTIVE

This paper discusses the possible etiologies for the proportionate short stature of a female individual and provides data to allow the diagnosis of future cases of Turner Syndrome (TS) in paleopathology.

MATERIALS

Skeleton of a 26-years-old maid, from the Coimbra Identified Skeletal Collection, who died of measles in 1920.

METHODS

Macroscopic examination, imaging techniques, and metric analysis.

RESULTS

Her estimated height is 138.91-144.3 cm, approximately three standard deviations below the average female stature for early 20th century Portugal. The crural, brachial, humero-femoral, and intermembral indexes show a proportionate body, uncommon in dwarfism. Small skull with prominent frontal, maxillary prognathism, enamel hypoplasia, cribra orbitalia, porotic hyperostosis, proliferative reaction in the petrous portion of the temporal, obliterated sagittal suture, oval foramen magnum, and small mandible with masculine features. The sternal ends of the ribs are wider and vertebrae present developmental defects (e.g. atlas with both left transverse foramina and posterior tubercle open, absence of the right transverse foramen in the axis, sacrum with six vertebrae).

CONCLUSIONS

The differential diagnosis point to a possible case of Turner Syndrome.

SIGNIFICANCE

This study describes the features of Turner Syndrome and provide detail metric analysis of this individual, which will be useful for future paleopathological diagnoses.

LIMITATIONS

The confirmation of the diagnosis will only be possible through genetic analysis.

SUGGESTIONS FOR FURTHER RESEARCH

Reanalysis of skeletal individuals with short stature to detect possible cases of Turner Syndrome.

An iPS cell line SDUBMSi0011-A from a multiple epiphyseal dysplasia patient carrying c. 1076T > G mutation in the SMOC2 gene

SMOC2 gene encodes a modular extracellular protein and its mutation causes multiple epiphyseal dysplasia (MED) which characterized by short stature and osteoarthritis. Here, we generated an induced pluripotent stem cell line from a MED patient with c. 1076T > G transition mutation in SMOC2 gene. The iPSCs line has a normal male karyotype and the same mutation as the MED patient. It also expresses pluripotent markers and can differentiate into the three germ layers.

Study on pathogenic genes of dwarfism disease by next-generation sequencing

BACKGROUND

There are many factors that lead to dwarfism, and the mechanism has not yet been elucidated. Next-generation sequencing may identify candidate-related gene mutations, which may clarify the molecular cause.

AIM

To analyze genetic variation by using a constructed panel related to dwarfism by utilizing next-generation sequencing platform sequencing analysis to screen candidate-related gene mutations.

METHODS

Physical and laboratory characteristics, including clinical examination, growth hormone drug challenge test, serum insulin-like growth factor-1 (IGF-1), IGF binding protein 3, other related tests, imaging examination, and chromosome karyotyping, were analyzed. Next-generation sequencing was performed to analyze pathogenicity variability.

RESULTS

In the 39 dwarfism patients, 10 had pathogenicity variability. Gene variation was found in the OBSL1, SLC26A2, PTPN11, COL27AI, HDAC6, CUL7, FGFR3, DYNC2H1, GH1, and ATP7B genes. Of the 10 patients with pathogenicity variability, the related physical characteristics included double breast development and growth hormone deficiency, enuresis and indirect inguinal hernia on the left, two finger distance of 70.2 cm, head circumference of 49.2 cm, ischium/lower body length of 1.8 cm, weak limb muscles, and partial growth hormone deficiency. After 6 mo of growth hormone therapy, the concentrations of IGF-1 and IGF binding protein 3 increased from 215.2 ± 170.3 to 285.0 ± 166.0 and 3.9 ± 1.4 to 4.2 ± 1.1, respectively.

CONCLUSION

OBSL1, SLC26A2, PTPN11, COL27AI, HDAC6, CUL7, FGFR3, DYNC2H1, GH1, and ATP7B genes may be related to the incidence of dwarfism, and more research needs to be performed to elucidate the mechanism.

Expanding the phenotypic spectrum of RPL13-related skeletal dysplasia

RPL13-related disorder is a newly described skeletal dysplasia characterized as a form of spondyloepimetaphyseal dysplasia with normal birth length, early postnatal growth deficiency, severe short stature, and genu varum. We present a 9-year-old male with a history of lower leg pain and concern for an unspecified form of multiple epiphyseal dysplasia (MED). Exome sequencing revealed a de novo heterozygous RPL13 c.477+1G>A (IVS4+1G>A) pathogenic variant. This is the first identified case of an individual with an RPL13-related skeletal dysplasia, normal height, and radiographs consistent with a form of MED and Legg-Calve-Perthes-like disease. This case expands the phenotype of RPL13-related disorders.

Age Dependent Progression of Multiple Epiphyseal Dysplasia and Pseudoachondroplasia Due to Heterozygous Mutations in COMP Gene

Dominantly inherited mutations in COMP gene encoding cartilage oligomeric matrix protein may cause two dwarfing skeletal dysplasias, milder multiple epiphyseal dysplasia (MED) and more severe pseudoachondroplasia (PSACH). We studied the phenotype and X-rays of 11 patients from 5 unrelated families with different COMP mutations. Whole exome and/or Sangers sequencing were used for molecular analyses. Four to ten X-ray images of hands hips, knees or spine were available for each patient for retrospective analyses. Eight patients with MED have mutation c.1220G&gt;A and 3 children with PSACH mutations c.1359C&gt;A, c.1336G&gt;A, or the novel mutation c.1126G&gt;T in COMP. Progressive failure in growth developed in all patients from early childhood and resulted in short stature &lt; 3rd percentile in 7 patients and very short stature &lt; 1st percentile in four. Most patients had joint pain since childhood, severe stiffness in shoulders and elbows but increased mobility in wrists. Six children had bowlegs and two had knock knees. In all patients, X-rays of hands, hips and knees showed progressive, age-dependent skeletal involvement more pronounced in the epiphyses of long rather than short tubular bones. Anterior elongation and biconvex configuration of vertebral bodies were more conspicuous for kids. Six children had correction of knees and two adults had hip replacement. Skeletal and joint impairment in patients with MED and PSACH due to COMP mutation start in early childhood. Although the clinical severity is mutation and age dependent, many symptoms represent a continuous phenotypic spectrum between both diseases. Most patients may benefit from orthopaedic surgeries.

A novel COMP mutation in a Chinese family with multiple epiphyseal dysplasia

Background

Multiple epiphyseal dysplasia (MED) is a skeletal disorder characterized by delayed and irregular ossification of the epiphyses and early-onset osteoarthritis. At least 66% of the reported autosomal dominant MED (AD-MED) cases are caused by COMP mutations.

Methods

We recruited a four-generation Chinese family with early-onset hip osteoarthritis, flatfoot, brachydactyly, and mild short stature. An assessment of the family history, detailed physical examinations, and radiographic evaluations were performed on the proband and other family members, followed by the performance of whole-exome sequencing (WES). The pathogenicity of the candidate mutation was also analyzed.

Results

An AD-MED family with 10 affected members and 17 unaffected members was recruited. The main radiographic findings were symmetrical changes in the dysplastic acetabulum and femoral heads, irregular contours of the epiphyses, a shortened femoral neck, and flatfoot. Lower bone density was also observed in the ankle joints, wrist joints, and knees, as well as irregular vertebral end plates. In the proband, we identified the missense mutation c.1153G > T (p. Asp385Tyr), located in exon 11 of the COMP gene. This mutation was assessed as 'pathogenic' because of its low allele frequency and its high likelihood of co-segregation with disease in the reported family. Sanger sequencing validated the novel heterozygous mutation c.1153G > T (p. Asp385Tyr) in exon 11 of COMP in all affected individuals in the family.

Conclusions

Our results underlined a key role of the Asp385 amino acid in the protein function of COMP and confirmed the pathogenicity of the COMP (c.1153G > T; p. Asp385Tyr) mutation in AD-MED disease. We have therefore expanded the known mutational spectrum of COMP and revealed new phenotypic information for AD-MED.

A novel homozygous missense variant in MATN3 causes spondylo-epimetaphyseal dysplasia Matrilin 3 type in a consanguineous family

Spondylo-epimetaphyseal dysplasia Matrilin 3 type (SEMD) is a rare autosomal recessive skeletal dysplasia characterized by short stature, abnormalities in the vertebral bodies and long bones, especially the lower limbs. We enrolled a consanguineous family from Pakistan in which multiple siblings suffered from severe skeletal dysplasia. The six affected subjects ranged in heights from 100 to 136 cm (~-6 standard deviation). Lower limb abnormalities with variable varus and valgus deformities and joint dysplasia were predominant features of the clinical presentation. Whole exome sequencing (WES) followed by Sanger sequencing identified a missense variant, c.542G > A, p.(Arg181Gln) in MATN3 as the genetic cause of the disorder. The variant was homozygous in all affected individuals while the obligate carriers had normal heights with no skeletal symptoms, consistent with a recessive pattern of inheritance. Multiple sequence alignment revealed that MATN3 domain affected by the variant is highly conserved in orthologous proteins. The c.542G > A, p.(Arg181Gln) variant is only the fourth variant in MATN3 causing an autosomal recessive disorder and thus expands the genotypic spectrum.

High Prevalence of Growth Plate Gene Variants in Children With Familial Short Stature Treated With GH

CONTEXT

Familial short stature (FSS) is a term describing a growth disorder that is vertically transmitted. Milder forms may result from the combined effect of multiple genes; more severe short stature is suggestive of a monogenic condition. The etiology of most FSS cases has not been thoroughly elucidated to date.

OBJECTIVES

To identify the genetic etiology of severe FSS in children treated with GH because of the diagnosis of small for gestational age or GH deficiency (SGA/GHD).

DESIGN, SETTINGS, AND PATIENTS

Of 736 children treated with GH because of GHD/SGA, 33 with severe FSS (life-minimum height -2.5 SD or less in both the patient and shorter parent) were included in the study. The genetic etiology was known in 5 of 33 children prior to the study [ACAN (in 2], NF1, PTPN11, and SOS1). In the remaining 28 of 33, whole-exome sequencing was performed. The results were evaluated using American College of Medical Genetics and Genomics standards and guidelines.

RESULTS

In 30 of 33 children (90%), we found at least one variant with potential clinical significance in genes known to affect growth. A genetic cause was elucidated in 17 of 33 (52%). Of these children, variants in growth plate-related genes were found in 9 of 17 [COL2A1, COL11A1, and ACAN (all in 2), FLNB, FGFR3, and IGF1R], and IGF-associated proteins were affected in 2 of 17 (IGFALS and HMGA2). In the remaining 6 of 17, the discovered genetic mechanisms were miscellaneous (TRHR, MBTPS2, GHSR, NF1, PTPN11, and SOS1).

CONCLUSIONS

Single-gene variants are frequent among families with severe FSS, with variants affecting the growth plate being the most prevalent.

Homozygous Type IX collagen variants (COL9A1, COL9A2, and COL9A3) causing recessive Stickler syndrome-Expanding the phenotype

Stickler syndrome (SS) is characterized by ophthalmic, articular, orofacial, and auditory manifestations. SS is usually autosomal dominantly inherited with variants in COL2A1 or COL11A1. Recessive forms are rare but have been described with homozygous variants in COL9A1, COL9A2, and COL9A3 and compound heterozygous COL11A1 variants. This article expands phenotypic descriptions in recessive SS due to variants in genes encoding Type IX collagen. Clinical features were assessed in four families. Genomic DNA samples derived from venous blood were collected from family members. Six affected patients were identified from four pedigrees with variants in COL9A1 (one family, one patient), COL9A2 (two families, three patients), and COL9A3 (one family, two patients). Three variants were novel. All patients were highly myopic with congenital megalophthalmos and abnormal, hypoplastic vitreous gel, and all had sensorineural hearing loss. One patient had severe arthropathy. Congenital megalophthalmos and myopia are common to dominant and recessive forms of SS. Sensorineural hearing loss is more common and severe in recessive SS. We suggest that COL9A1, COL9A2, and COL9A3 be added to genetic screening panels for patients with congenital hearing loss. Although recessive SS is rare, early diagnosis would have a high impact for children with potentially dual sensory impairment, as well as identifying risk to future children.

[Targeted binding of estradiol with ESR1 promotes proliferation of human chondrocytes in vitro by inhibiting activation of ERK signaling pathway]

OBJECTIVE

To investigate the effect of estradiol (E2)/estrogen receptor 1 (ESR1) on the proliferation of human chondrocytes in vitro and explore the molecular mechanism.

METHODS

The Ad-Easy adenovirus packaging system was used to construct and package the ESR1-overexpressing adenovirus Ad-ESR1. Western blotting and qPCR were used to detect the expression of ESR1 protein and mRNA in human chondrocyte C28I2 cells. In the cells treated with different adenoviruses, the effects of E2 were tested on the expressions of proteins related with cell autophagy and apoptosis and the phosphorylation of ERK signaling pathway using Western blotting. Immunofluorescence assay was used to observe the intracellular autophagic flow, flow cytometry was performed to analyze the cell apoptosis rate and the cell cycle changes, and qPCR was used to detect the expressions of PCNA, cyclin B1 and cyclin D1 mRNAs. The inhibitory effect of the specific inhibitor of ERK on the expressions of autophagy- and apoptosis-related genes at both the protein and mRNA levels were detected using Western blotting and qPCR.

RESULTS

Transfection with the recombinant adenovirus overexpressing ESR1 and E2 treatment of C28I2 cells significantly enhanced the expressions of autophagy-related proteins LC3, ATG7, promoted the colocalization of LC3 and LAMP1 in the cytoplasm, increased the expressions of the proliferation-related marker genes PCNA, cyclin B1 and cyclin D1, and supressed the expressions of cleaved caspase-3, caspase-12 and pERK. RNA interference of ESR1 obviously lowered the expression levels of autophagy-related proteins in C28I2 cells, causing also suppression of the autophagic flow, increments of the expressions of apoptosis-related proteins and pERK, and down-regulated the expressions of the proliferation marker genes. Blocking ERK activation with the ERK inhibitor obviously inhibited the effects of E2/ESR1 on autophagy, proliferationrelated gene expressions and cell apoptosis.

CONCLUSIONS

The targeted binding of E2 with ESR1 promotes the proliferation of human chondrocytes in vitro possibly by inhibiting the activation of ERK signaling pathway to promote cell autophagy and induce cell apoptosis.

Articulated Hip Distraction for Impingement of the Deformed Femoral Head in a Patient with Multiple Epiphyseal Dysplasia: A Case Report

CASE

A 14-year-old boy with multiple epiphyseal dysplasia (MED) presented with right hip pain and stiffness. Radiographs revealed a deep notch at the superolateral part of the femoral head, which abutted the lateral corner of the acetabulum. Articulated hip distraction (AHD) was used to reduce the femoral head and obliterate the notch. At the 4-year follow-up, the radiographs showed a well-preserved joint space, and the patient had functional improvement.

CONCLUSION

AHD may be an effective way to address and obliterate a superolateral femoral head notch and promote regeneration of the femoral head in a patient with MED.

Lubricin binds cartilage proteins, cartilage oligomeric matrix protein, fibronectin and collagen II at the cartilage surface

Lubricin, a heavily O-glycosylated protein, is essential for boundary lubrication of articular cartilage. Strong surface adherence of lubricin is required given the extreme force it must withstand. Disulfide bound complexes of lubricin and cartilage oligomeric matrix protein (COMP) have recently been identified in arthritic synovial fluid suggesting they may be lost from the cartilage surface in osteoarthritis and inflammatory arthritis. This investigation was undertaken to localise COMP-lubricin complexes within cartilage and investigate if other cartilage proteins are involved in anchoring lubricin to the joint. Immunohistochemical analysis of human cartilage biopsies showed lubricin and COMP co-localise to the cartilage surface. COMP knockout mice, however, presented with a lubricin layer on the articular cartilage leading to the further investigation of additional lubricin binding mechanisms. Proximity ligation assays (PLA) on human cartilage biopsies was used to localise additional lubricin binding partners and demonstrated that lubricin bound COMP, but also fibronectin and collagen II on the cartilage surface. Fibronectin and collagen II binding to lubricin was confirmed and characterised by solid phase binding assays with recombinant lubricin fragments. Overall, COMP, fibronectin and collagen II bind lubricin, exposed on the articular cartilage surface suggesting they may be involved in maintaining essential boundary lubrication.

Extensive Arthroscopic Chondroplasty for Cartilage Hyperplasia of the Femoral Condyle Causing Recurrent Knee Locking in a Patient With Multiple Epiphyseal Dysplasia

Multiple epiphyseal dysplasia is a genetically heterogeneous group of diseases causing altered enchondral ossification. It may affect the knee, among other joints, with variable clinical manifestations. In this report, we present a case of a young adult patient with multiple epiphyseal dysplasia, presenting recurrent catching and locking of the knee due to hyperplastic irregular cartilage. Although radiographs and magnetic resonance imaging of his knee were inconclusive with regard to the source of symptoms, arthroscopic examination revealed a flap of irregular and extensive hypertrophic cartilage of the medial femoral condyle that was causing catching during knee motions. This was treated by extensive arthroscopic resection of the hypertrophic cartilage with the knee held in a deep flexion position and symptoms resolved uneventfully. The case emphasizes the importance of a thorough arthroscopic examination when radiographs and magnetic resonance imaging may overlook the specific source for symptoms, and shows the potential for symptom resolution by arthroscopic intervention in these unusual circumstances.

A suspected genetic form of bilateral osteochondritis dissecans of the knee in a Dutch family

Osteochondritis dissecans (OCD) mostly has an idiopathic origin, but syndromic and familial forms have been reported. Mutations of the aggrecan (ACAN) and COL9A2 genes are associated with familial OCD, but these patients present with syndromic features. This article describes a mother and a daughter who both have bilateral OCD of the medial femoral condyles, and the monozygotic twin sister of the mother who has confirmed unilateral OCD (and possible bilateral OCD) of the medial femoral condyle. No short stature or any other syndromic features were present. None of the syndromic features associated with ACAN or COL9A2 mutations or any other known syndromes were present in this case. This case suggests a possible unknown genetic anomaly.