Congenital fascial dystrophy: abnormal composition of the fascia

New clinical classification of stiff skin syndrome

BACKGROUND

Stiff skin syndrome (SSS) is a rare disease characterized by thickened, indurated skin and limited joint movement. Multiple diverse phenotypes have been reported, and the correlation of severity with the clinical heterogeneity and histopathological findings of SSS needs to be refined.

OBJECTIVE

To define subtypes based on clinical features and predict the prognosis of a new SSS classification.

METHODS

Eighty-three patients with SSS were retrospectively reviewed for clinicopathological manifestations and routine laboratory workup, including 59 cases obtained from a PubMed search between 1971 and 2022 and 24 cases diagnosed in our department between 2003 and 2022.

RESULTS

Among the 83 patients, 27.7, 41, and 31.3% had classic widespread, generalized segmental, and localized SSS, respectively. Joint immobility was present in 100, 71, and 20% of classic, generalized, and localized cases, respectively. Histopathologic findings were common among the 3 groups, and based on that, we further found a difference in the distribution of proliferative collagen. 54.5% of classic and 50% of generalized cases occurred throughout the dermis or the subcutis, whereas 76% of localized cases were mainly involved in the reticular dermis or subcutis. In patients with incipient localized SSS, 42% (21/50) developed generalized SSS, and only 6% (3/50) progressed to classic SSS, whereas more than half of the incipient generalized SSS cases (60.6%, 20/33) developed classic SSS.

LIMITATIONS

This retrospective study was limited to previously published cases with limited data.

CONCLUSIONS

We propose a distinct clinical classification characterized by lesion distribution, including classic widespread, generalized segmental, and localized SSS, associated with disease severity and prognosis.

Classification and rising medication therapy in stiff skin syndrome: A case report and literature review

Stiff skin syndrome (SSS) is a rare disorder characterized by skin induration and limited joint mobility in the absence of visceral, musculoskeletal, vascular, or immunologic abnormalities. Distinctive subsets of SSS could be distinguished by various manifestation and mechanism, which accounts for the high heterogeneity in SSS cases. Although rehabilitation training remains the mainstay of management, rising medications has drawn awareness in recent years, owing to the potential efficacy. Nevertheless, experience was limited, especially in widespread SSS. We report on a 5-year-old girl with widespread SSS, whose lesion stopped progressing after combination therapy by mycophenolic acid (MPA) and losartan (LST) in addition to rehabilitation exercise. Despite limited experience, a combined therapy of MPA and LST seems to be effective in retarding progression of widespread SSS.

Pro-Fibrotic Phenotype in a Patient with Segmental Stiff Skin Syndrome via TGF-β Signaling Overactivation

Transforming growth factor β (TGF-β) superfamily signaling pathways are ubiquitous and essential for several cellular and physiological processes. The overexpression of TGF-β results in excessive fibrosis in multiple human disorders. Among them, stiff skin syndrome (SSS) is an ultrarare and untreatable condition characterized by the progressive thickening and hardening of the dermis, and acquired joint limitations. SSS is distinct in a widespread form, caused by recurrent germline variants of FBN1 encoding a key molecule of the TGF-β signaling, and a segmental form with unknown molecular basis. Here, we report a 12-year-old female with segmental SSS, affecting the right upper limb with acquired thickening of the dermis evident at the magnetic resonance imaging, and progressive limitation of the elbow and shoulder. To better explore the molecular and cellular mechanisms that drive segmental SSS, several functional studies on patient's fibroblasts were employed. We hypothesized an impairment of TGF-β signaling and, consequently, a dysregulation of the associated downstream signaling. Lesional fibroblast studies showed a higher phosphorylation level of extracellular signal-regulated kinase 1/2 (ERK1/2), increased levels of nuclear factor-kB (NFkB), and a nuclear accumulation of phosphorylated Smad2 via Western blot and microscopy analyses. Quantitative PCR expression analysis of genes encoding key extracellular matrix proteins revealed increased levels of COL1A1, COL3A1, AGT, LTBP and ITGB1, while zymography assay reported a reduced metalloproteinase 2 enzymatic activity. In vitro exposure of patient's fibroblasts to losartan led to the partial restoration of normal transforming growth factor β (TGF-β) marker protein levels. Taken together, these data demonstrate that in our patient, segmental SSS is characterized by the overactivation of multiple TGF-β signaling pathways, which likely results in altered extracellular matrix composition and fibroblast homeostasis. Our results for the first time reported that aberrant TGF-β signaling may drive the pathogenesis of segmental SSS and might open the way to novel therapeutic approaches.

Stony Hard Skin During Early Infancy

Stiff skin syndrome is a rare disease causing stony hard induration of skin usually in early childhood. We report a case of 12 years old boy who presented to our clinic with biopsy showing adipocyte entrapment which we believe is an unrecognized key pathological finding in diagnosis of this entity.

The ocular phenotype of stiff-skin syndrome

PURPOSE Stiff skin syndrome (SSS; MIM#184900) is a rare autosomal dominantly inherited Mendelian disorder characterised by thickened and stone-hard indurations of the skin, mild hypertrichosis, and limitation of joint mobility with flexion contractures. It is autosomal dominant with high penetrance and results from mutations in the fibrillin 1 (FBN1; MIM*134797) gene. Here we present the associated ocular phenotype in a two generation nonconsanguineous Northern Irish family.METHODS The affected patients underwent complete ophthalmic and orthoptic assessment and genetic testing.RESULTS All three patients had ophthalmoplegia of varying degrees. Direct sequencing of the FBN1 gene detected a heterozygous pathogenic mutation (c.4710G>C; p.Trp1570Cys) in all affected patients.CONCLUSIONS This is the first report of ophthalmoplegia in association with SSS.

Stiff skin syndrome--case report

Stiff skin syndrome is a rare scleroderma-like disorder of unknown etiology characterized by stone-hard indurations of skin, mild hypertrichosis and limited joint mobility. No effective treatment has yet been found. Exercises and rehabilitative therapy are important in maintaining the patient's quality of life. The authors present a case of a two-year-old boy with progressive skin hardening since he was eight-month old and secondary restricted joint mobility, diagnosed as Stiff skin syndrome.

Mutations in fibrillin-1 cause congenital scleroderma: stiff skin syndrome

The predisposition for scleroderma, defined as fibrosis and hardening of the skin, is poorly understood. We report that stiff skin syndrome (SSS), an autosomal dominant congenital form of scleroderma, is caused by mutations in the sole Arg-Gly-Asp sequence-encoding domain of fibrillin-1 that mediates integrin binding. Ordered polymers of fibrillin-1 (termed microfibrils) initiate elastic fiber assembly and bind to and regulate the activation of the profibrotic cytokine transforming growth factor-beta (TGFbeta). Altered cell-matrix interactions in SSS accompany excessive microfibrillar deposition, impaired elastogenesis, and increased TGFbeta concentration and signaling in the dermis. The observation of similar findings in systemic sclerosis, a more common acquired form of scleroderma, suggests broad pathogenic relevance.

The fascia of the limbs and back--a review

Although fasciae have long interested clinicians in a multitude of different clinical and paramedical disciplines, there have been few attempts to unite the ensuing diverse literature into a single review. The current article gives an anatomical perspective that extends from the gross to the molecular level. For expediency, it deals only with fascia in the limbs and back. Particular focus is directed towards deep fascia and thus consideration is given to structures such as the fascia lata, thoracolumbar fascia, plantar and palmar fascia, along with regional specializations of deep fascia such as retinacula and fibrous pulleys. However, equal emphasis is placed on general aspects of fascial structure and function, including its innervation and cellular composition. Among the many functions of fascia considered in detail are its ectoskeletal role (as a soft tissue skeleton for muscle attachments), its importance for creating osteofascial compartments for muscles, encouraging venous return in the lower limb, dissipating stress concentration at entheses and acting as a protective sheet for underlying structures. Emphasis is placed on recognizing the continuity of fascia between regions and appreciating its key role in coordinating muscular activity and acting as a body-wide proprioceptive organ. Such considerations far outweigh the significance of viewing fascia in a regional context alone.