The autosomal dominant chondrodystrophies, the Stickler type 2 and Marshall syndromes, are characterized by facial abnormalities, vision deficits, hearing loss, and articular joint issues resulting from mutations in COL11A1. Zebrafish carry two copies of the Col11a1 gene, designated Col11a1a and Col11a1b. Col11a1a is located on zebrafish chromosome 24 and Col11a1b is located on zebrafish chromosome 2. Expression patterns are distinct for Col11a1a and Col11a1b and Col11a1a is most similar to COL11A1 that is responsible for human autosomal chondrodystrophies and the gene responsible for changes in the chondrodystrophic mouse model cho/cho. We investigated the function of Col11a1a in craniofacial and axial skeletal development in zebrafish using a knockdown approach. Knockdown revealed abnormalities in Meckel\'s cartilage, the otoliths, and overall body length. Similar phenotypes were observed using a CRISPR/Cas9 gene-editing approach, although the CRISPR/Cas9 effect was more severe compared to the transient effect of the antisense morpholino oligonucleotide treatment. The results of this study provide evidence that the zebrafish gene for Col11a1a is required for normal development and has similar functions to the mammalian COL11A1 gene. Due to its transparency, external fertilization, the Col11a1a knockdown, and knockout zebrafish model systems can, therefore, contribute to filling the gap in knowledge about early events during vertebrate skeletal development that are not as tenable in mammalian model systems and help us understand Col11a1-related early developmental events.

We report the clinical findings of 26 individuals from 16 unrelated families carrying variants in the COL2A1 or COL11A1 genes. Using Sanger and next-generation sequencing, 11 different COL2A1 variants (seven novel), were identified in 13 families (19 affected individuals), all diagnosed with Stickler syndrome (STL) type 1. In nine families, the COL2A1 disease-causing variant arose de novo. Phenotypically, we observed myopia (95%) and retinal detachment (47%), joint hyperflexibility (92%), midface retrusion (84%), cleft palate (53%), and various degrees of hearing impairment (50%). One patient had a splenic artery aneurysm. One affected individual carrying pathogenic variant in COL2A1 showed no ocular signs including no evidence of membranous vitreous anomaly. In three families (seven affected individuals), three novel COL11A1 variants were found. The propositus with a de novo variant showed an ultrarare Marshall/STL overlap. In the second family, the only common clinical sign was postlingual progressive sensorineural hearing impairment (DFNA37). Affected individuals from the third family had typical STL2 signs. The spectrum of disease phenotypes associated with COL2A1 or COL11A1 variants continues to expand and includes typical STL and various bone dysplasias, but also nonsyndromic hearing impairment, isolated myopia with or without retinal detachment, and STL phenotype without clinically detectable ocular pathology.

Sweet syndrome is rare in the pediatric population and usually responds well to treatment, resolving without sequelae. Marshall syndrome is a rare pediatric skin disease characterized by loss of elastic tissue (cutis laxa) secondary to acquired, localized neutrophilic dermatitis without any internal organ involvement. Only few cases of Marshall syndrome (acquired cutis laxa type II) have been reported. Systemic steroids and dapsone show excellent results in Sweet syndrome. Although there is no satisfactory treatment for cutis laxa, dapsone can be used in the acute phase for control of swelling.

BACKGROUND: Stickler syndrome is a group of collagenopathies characterized by ophthalmic, skeletal, and orofacial abnormalities, with the degree of symptoms varying among patients. Mutations in the COL2A1, COL11A1, and COL11A2 procollagen genes cause Stickler syndrome. Marshall syndrome, caused by a COL11A1 mutation, has clinical overlap with Stickler syndrome.
METHODS: A 2-year-old Japanese boy was presented to our hospital with short stature (79.1 cm, -2.52 standard deviation). His past medical history was significant for soft cleft palate and bilateral cataracts. He had a flat midface, micrognathia, and limitations in bilateral elbow flexion. Radiographs showed mild spondyloepiphyseal dysplasia. Initially, we suspected Marshall syndrome, but no mutation was identified in COL11A1. At 8 years old, his height was 116.2 cm (-1.89 standard deviation), and his orofacial characteristics appeared unremarkable. We analyzed the COL2A1 gene and found a novel heterozygous mutation (c.1142 G > A, p.Gly381Asp).
CONCLUSIONS: In this case report, we identify a novel missense mutation in the COL2A1 gene in a patient with Stickler syndrome type 1, and we describe age-related changes in the clinical phenotype with regard to orofacial characteristics and height. Genetic analysis is helpful for the diagnosis of this clinically variable and genetically heterogeneous disorder.

BACKGROUND: PFAPA syndrome is the most frequent periodic fever syndrome in non-Mediterranean patients. The pathogenesis is unclear and the treatment is purely symptomatic and not standardized. The aim of this study was to assess colchicine\'s efficacy as prophylactic treatment in PFAPA syndrome and to identify factors able to predict response to treatment.
METHODS: We performed a retrospective, multicentric, cohort study of PFAPA patients under colchicine prophylaxis. PFAPA diagnosis was established according to Feder\'s criteria. Medical records were reviewed and analyzed for demographic, clinical and laboratory data. We distinguished one responder\'s group, defined as patients who had no more or twice fewer crises under colchicine and another one of non-responders. Subgroup analyses were performed using non-parametric Mann-Whitney test for quantitative data and calculating odds ratio and confidence interval for qualitative data. Difference between the two groups was considered significant for P-value<0.05 or a confidence interval different from 1.
CONCLUSIONS: Twenty children, 65% of whom were boys, were analyzed. Their mean age at disease onset was 2.3±1.5 years. Among the nine responder patients, five were MEFV (71%) heterozygotes: M694V mutation in four and V726A once. Heterozygous MEFV gene mutation tended to be more frequent in the responders group (71% versus 43%; OR=0.3 [0.03-2.7]). Non-responder patients had more chronic fatigue (82% versus 33%; OR=9 [1,14-71]) and had more oral aphtosis (82% versus 11%; OR=36 [1,7-141]) than the responders ones. Although not significant, colchicine treatment appeared more effective in patients with less complete PFAPA phenotype and MEFV heterozygosity.

Marshall syndrome and type II Stickler syndrome are caused by mutations in COL11A1, which codes for the proα1chain of collagen XI. Collagen XI is a minor fibrillar collagen co-expressed with collagen II in cartilage and the vitreous of the eye. Characteristic features of Marshall syndrome include midfacial hypoplasia, high myopia, and sensorineural-hearing deficit. Deletions, insertions, splice site, and missense mutations in COL11A1 have been identified in Stickler syndrome and Marshall syndrome patients. In this study, we describe the clinical presentations of seven patients with Marshall syndrome from three unrelated Saudi families, inherited as autosomal dominant (two families) and autosomal recessive (one family). Cardinal clinical features of Marshall syndrome are manifested in all patients. One patient had ectodermal abnormalities. Mutations (c.2702G > A in exon 34,IVS50 + 1G > A, and IVS50 + lG > C) were identified in COL11A1 in affected members. Interestingly, the first report of autosomal recessive Marshall syndrome was from Saudi Arabia caused by the same mutation (c.2702G > A, p.Gly901Glu) as in one of our families. This study depicts detailed phenotypic and genetic description of dominant and recessive forms of Marshall syndrome due to COL11A1 mutations.