Ehlers Danlos syndrome, kyphoscoliotic type due to Lysyl Hydroxylase 1 deficiency in two children without congenital or early onset kyphoscoliosis

Ehlers-Danlos syndromes: importance of defining the type

Ehlers-Danlos syndromes (EDS) is an umbrella term describing 14 types, of which 13 are rare and monogenic, with overlapping features of joint hypermobility, skin, and vascular fragility, and generalised connective tissue friability. Hypermobile EDS currently has no identified genetic cause. Most of the rare monogenic EDS types can have neurological features, which are often part of major or minor diagnostic criteria for each type. This review aims to highlight the neurological features and other key characteristics of these EDS types. This should improve recognition of these features, enabling more timely consideration and confirmation or exclusion through genetic testing. In practice, many healthcare professionals still refer to patients as having 'EDS'. However, the different EDS types have distinct clinical features as well as different underlying genetic causes and pathogenic mechanisms, and each requires bespoke management and surveillance. Defining the EDS type is therefore crucial, as EDS is not in itself a diagnosis.

Features of Congenital Arthrogryposis Due to Abnormalities in Collagen Homeostasis, a Scoping Review

Congenital arthrogryposis (CA) refers to the presence of multiple contractures at birth. It is a feature of several inherited syndromes, notable amongst them are disorders of collagen formation. This review aims to characterize disorders that directly or indirectly impact collagen structure and function leading to CA in search for common phenotypic or pathophysiological features, possible genotype-phenotype correlation, and potential novel treatment approaches based on a better understanding of the underlying pathomechanism. Nine genes, corresponding to five clinical phenotypes, were identified after a literature search. The most notable trend was the extreme phenotype variability. Clinical features across all syndromes ranged from subtle with minimal congenital contractures, to severe with multiple congenital contractures and extra-articular features including skin, respiratory, or other manifestations. Five of the identified genes were involved in the function of the Lysyl Hydroxylase 2 or 3 enzymes, which enable the hydroxylation and/or glycosylation of lysyl residues to allow the formation of the collagen superstructure. Whilst current treatment approaches are post-natal surgical correction, there are also potential in-utero therapies being developed. Cyclosporin A showed promise in treating collagen VI disorders although there is an associated risk of immunosuppression. The treatments that could be in the clinical trials soon are the splice correction therapies in collagen VI-related disorders.

Vascular Injury After Scoliosis Correction in Ehlers-Danlos Syndrome: Proceed With Caution

Ehlers-Danlos syndrome (EDS) is a rare inherited connective tissue disorder characterized by collagen synthesis disruption, resulting in joint hyperlaxity, skin and vascular fragility, and bleeding diathesis. Patients with EDS are susceptible to spinal deformities, with scoliosis accounting for up to 23.4% of musculoskeletal abnormalities. Conservative management is often trialed initially; however, severe scoliosis can lead to significant sagittal imbalance and cardiopulmonary compromise. Surgical intervention for scoliosis correction in patients with EDS presents unique challenges because of tissue fragility and an increased risk of vascular and wound complications. This case report discusses a 20-year-old man with type II EDS and scoliosis, who experienced retroperitoneal compartment syndrome, significant left lower extremity weakness, and loss of sensation after scoliosis correction surgery. The report also provides an overview of the existing literature on scoliosis surgery outcomes in patients with EDS, highlighting the need for heightened vigilance and cautious surgical approaches.

Single-level posterior lumbar fusions in patients with Ehlers Danlos Syndrome not found to be associated with increased postoperative adverse events or five-year reoperations

Background

Ehlers Danlos Syndrome (EDS) is a rare connective tissue disorder that results from mutations in collagen genes. Potentially related to laxity and resultant degenerative changes, adult EDS patients may require posterior lumbar fusion (PLF). However, with low numbers, adequately powered outcome studies have been limited. The purpose of this study was to investigate risk of complications, readmissions and reoperations in adult patients with EDS following single-level PLF.

Methods

A retrospective study using the 2010 to 2020 MSpine Pearldiver dataset was performed. Adult patients undergoing single-level PLF (excluding any with anterior procedures) with and without EDS for which at least 90-day follow up was available were identified. Any cases performed for trauma, tumor, or infection were excluded.Single-level PLF EDS patients were then matched 1:4 with PLF non-EDS patients based on age, sex, and Elixhauser Comorbidity Index (ECI). Rates of ninety-day any, severe, and minor adverse events as well as readmissions were tabulated and compared with chi-square tests. Multivariate logistical regression was then performed (controlling for age, sex, and ECI).Reoperation surgeries over five years were assessed, Kaplan-Meier survival curves generated, and curves of those with and without EDS were compared with log rank test.

Results

In total, there were 170,100 single-level PLF case identified, of which 242 (0.14%) had EDS. After matching, there were 957 without EDS and 239 with EDS. On multivariate regression, there were no significant differences in 90-day any, severe, or minor adverse events, or readmissions (p>0.05 for each). Over five years, there were also not significant differences in rates of reoperation (p> 0.05).

Conclusions

For EDS patients undergoing PLF, the current study identified similar 90-day adverse events and 5-year reoperation rates compared to those without EDS. These findings may be useful for patient counseling and surgical planning for those with this rare condition.

The first case report of Kyphoscoliotic Ehlers-Danlos syndrome of chinese origin with a novel PLOD1 gene mutation

Background

Kyphoscoliotic Ehlers-Danlos syndrome (kEDS) is a rare autosomal recessive connective tissue disorder characterized by progressive kyphoscoliosis, congenital muscular hypotonia, marked joint hypermobility, and severe skin hyperextensibility and fragility. Deficiency of lysyl hydroxylase 1 (LH1) due to mutations of PLOD1 (procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1) gene has been identified as the pathogenic cause of kEDS (kEDS-PLOD1). Up to now, kEDS-PLOD1 has not been reported among Chinese population.

Case presentation

A 17-year-old Chinese male patient presenting with hypotonia, joint hypermobility and scoliosis was referred to our hospital. After birth, he was found to have severe hypotonia leading to delayed motor development. Subsequently, joint hypermobility, kyphoscoliosis and amblyopia were found. Inguinal hernia was found at age 5 years and closed by surgery. At the same time, he presented with hyperextensible and bruisable velvety skin with widened atrophic scarring after minor trauma. Dislocation of elbow joint was noted at age of 6 years. Orthopedic surgery for correction of kyphoscoliosis was performed at age 10 years. His family history was unremarkable. Physical examination revealed elevated blood pressure. Slight facial dysmorphologies including high palate, epicanthal folds, and down-slanting palpebral fissures were found. He also had blue sclerae with normal hearing. X-rays revealed severe degree of scoliosis and osteopenia. The Echocardiography findings were normal. Laboratory examination revealed a slightly elevated bone turnover. Based on the clinical manifestations presented by our patient, kEDS was suspected. Genetic analysis revealed a novel homozygous missense mutation of PLOD1 (c.1697 G > A, p.C566Y), confirming the diagnosis of kEDS-PLOD1. The patient was treated with alfacalcidol and nifedipine. Improved physical strength and normal blood pressure were reported after 12-month follow-up.

Conclusions

This is the first case of kEDS-PLOD1 of Chinese origin. We identified one novel mutation of PLOD1, extending the mutation spectrum of PLOD1. Diagnosis of kEDS-PLOD1 should be considered in patients with congenital hypotonia, progressive kyphoscoliosis, joint hypermobility, and skin hyperextensibility and confirmed by mutation analysis of PLOD1.

Rare Cases of PLOD1-Related Kyphoscoliotic Ehlers-Danlos Syndrome in a Korean Family Identified by Next Generation Sequencing

Kyphoscoliotic Ehlers-Danlos syndrome (kEDS) is an autosomal recessive connective tissue disorder characterized by muscular hypotonia, hyperextensible skin, skin fragility, joint hypermobility, and progressive kyphoscoliosis. The disorder results from a deficiency of the enzyme collagen lysyl hydroxylase 1 due to mutations in the gene PLOD1. We describe the rare cases of kEDS in Korean siblings with two novel compound heterozygous variants, c.926_934del (p.Leu309_Leu311del) and c.2170_2172del (p.Phe724del) in the PLOD1 gene. They had congenital hypotonia, joint laxity, skin hyperextensibility, Marfanoid habitus, high myopia and atrophic scarring. The younger sibling had an early-onset progressive kyphoscoliosis, while the older sibling showed mild scoliosis during childhood. Intrafamilial variability of the clinical severity and age of kyphoscoliosis onset observed in our cases.

Warmblood fragile foal syndrome type 1 mutation (PLOD1 c.2032G>A) is not associated with catastrophic breakdown and has a low allele frequency in the Thoroughbred breed

Background

Catastrophic fractures are among the most common cause of fatalities in racehorses. Several factors, including genetics, likely contribute to increased risk for fatal injuries. A variant in the procollagen‐lysine, 2‐oxoglutarate 5‐dioxygenase1 gene (PLOD1 c.2032G>A) was shown to cause Warmblood fragile foal syndrome type 1 (WFFS), a fatal recessive defect of the connective tissue. Screening of multiple horse breeds identified the presence of the WFFS allele in the Thoroughbred. PLOD1 is involved in cross‐linking of collagen fibrils and thus could potentially increase the risk of catastrophic breakdown.

Objectives

Estimate the frequency of the WFFS allele (PLOD1 c.2032G>A) and determine if it is a risk factor for catastrophic breakdown in the Thoroughbred.

Study design

Case–control genetic study.

Methods

Genomic DNA from hair and/or tissue samples was genotyped for the WFFS allele. Fisher’s Exact tests were performed to compare allele and carrier frequencies between the case cohort (catastrophic breakdown, n = 22) and several cohorts with no record of injury (n = 138 raced/trained at same track and season and n = 185 older than 7 years and raced during same season), nonracers (n = 92), and a random sample without consideration for racing history (n = 279).

Results

The frequency of the PLOD1 c.2032G>A variant in the Thoroughbred breed is low (1.2%). Seventeen of 716 Thoroughbreds tested were carriers (2.4%) and no WFFS homozygotes were detected. Only one catastrophic breakdown case carried the WFFS allele. No statistically significant difference in allele or carrier frequency was identified between case and control cohorts (P>0.05 in all comparisons performed).

Main limitations

This study evaluated cases from one single track.

Conclusions

This study demonstrated that the PLOD1 c.2032G>A associated with WFFS is present at very low frequency in Thoroughbreds and is not a genetic risk factor for catastrophic breakdown.

Complications in Children with Ehlers-Danlos Syndrome Following Spine Surgery: Analysis of the Pediatric National Surgery Quality Improvement Program Database

BACKGROUND

Ehlers-Danlos syndrome (EDS) is a group of rare congenital disorders of connective tissue that result in tissue fragility and joint hyperextensibility. Owing to its rarity, outcomes of pediatric spine surgery in patients with EDS are poorly characterized. Although it has been suggested that complication rates are high, few studies have characterized these complications.

METHODS

Pediatric National Surgery Quality Improvement Program data from 2012-2016 were analyzed. Patients with EDS undergoing spine surgery were identified along with patients without EDS undergoing the same surgeries using International Classification of Diseases, Ninth Revision and Current Procedural Terminology codes.

RESULTS

Of 369,176 total patients, 279 were determined to have EDS. Of these, 56 patients underwent spine surgery; 46% were male and 54% were female (P = 0.108). Mean age at surgery was 11.59 years (P = 0.888) with a range of 1.77-17.33 years. The most common procedure was arthrodesis (n = 37). There were no differences in unplanned reoperations (n = 4, P = 0.119), wound infections or disruptions (n = 2, P = 0.670), or overall complications (n = 25, P = 0.751). Blood transfusions were required in 41% of patients with EDS, but this was not significant compared with patients without EDS undergoing the same procedures (n = 23, P = 0.580). The total amount of blood transfused (P = 0.508), length of hospital stay (P = 0.396), and total operative time (P = 0.357) were not different from control subjects.

CONCLUSIONS

Pediatric patients with EDS do not appear to be at a higher risk of bleeding or other complications during spine surgery as reported in past case series. This is the largest retrospective review of its kind that has been performed in this patient population.

Roles of PLODs in Collagen Synthesis and Cancer Progression

Collagen is the major component of extracellular matrix. Collagen cross-link and deposition depend on lysyl hydroxylation, which is catalyzed by procollagen-lysine, 2-oxoglutarate 5-dioxygenase (PLOD). Aberrant lysyl hydroxylation and collagen cross-link contributes to the progression of many collagen-related diseases, such as fibrosis and cancer. Three lysyl hydroxylases (LH1, LH2, and LH3) are identified, encoded by PLOD1, PLOD2, and PLOD3 genes. Expression of PLODs is regulated by multiple cytokines, transcription factors and microRNAs. Dysregulation of PLODs promotes cancer progression and metastasis, suggesting that targeting PLODs is potential strategy for cancer treatment. Here, we summarize the recent progress in the investigation of function and regulation of PLODs in normal tissue development and disease progression, especially in cancer.