Importance of early diagnosis of Stickler syndrome in newborns

Clinical and genetic characterization of autosomal recessive stickler syndrome caused by novel compound heterozygous mutations in the COL9A3 gene

Background

Stickler syndrome (STL) is a clinically variable and genetically heterogeneous collagenopathy characterized by ophthalmic, auditory, skeletal, and orofacial abnormalities. STL is mainly inherited in an autosomal dominant pattern with mutations in the COL2A1, COL11A1, and COL11A2 genes. Autosomal recessive forms are rare. However, 19 patients have been reported to date, with STL caused by homozygous or compound heterozygous mutations in genes that encode for the three chains of type IX collagen: COL9A1, COL9A2, and COL9A3.

Methods

Genetic analysis was performed using the next‐generation sequencing of 166 genes associated with skeletal disorders and sequenced on an Ion Torrent S5 system with a minimum coverage of 100X. The two variants in the COL9A3 gene identified in the proband and the parents were confirmed by Sanger sequencing on an ABI3130xl sequencer.

Results

We describe a novel case of autosomal recessive Stickler syndrome caused by two undescribed mutations in the COL9A3 gene: c.268C>T (p.Arg90Ter) and c.1729C>T (p.Arg577Ter). The clinical features included severe sensorineural hearing loss, high myopia, vitreoretinal degeneration, and early‐onset arthropathy of the lower limbs. Radiography revealed mild spondyloepiphyseal dysplasia.

Conclusion

This case further expands the mutational and phenotypic spectrum of COL9A‐associated STL with a more severe presentation.

Ocular complications and prophylactic strategies in Stickler syndrome: a systematic literature review

BACKGROUND

Stickler syndrome is a collagenopathy caused by mutations in the genes COL2A1 (STL1) or COL11A1 (STL2). Affected patients manifest ocular, auditory, articular, and craniofacial manifestations in varying degrees. Ocular symptoms include myopia, retinal detachment, cataract, and glaucoma. The aim of this systematic review was to evaluate the prevalence of ocular manifestations and the outcome of prophylactic treatment on reducing the risk of retinal detachment.

METHOD

A systematic literature search was performed in the PubMed database. Information on the cross-study prevalence of myopia, retinal detachment, cataract, glaucoma, visual impairment, severity and age of onset of myopia and retinal detachments. Studies that reported on the outcome of prophylactic treatment against a control group were explored.

RESULTS

37 articles with 2324 individual patients were included. Myopia was found in 83% of patients, mostly of a moderate to severe degree. Retinal detachments occurred in 45% of patients. Generally, the first detachment occurred in the second decade of life in STL1 patients and later in STL2. Cataracts were more common in STL2 patients, 59% versus 36% in STL1. Glaucoma (10%) and visual impairment (blind: 6%; vision loss in one eye: 10%) were rare. Three studies reported on the effect of prophylactic treatment being protective.

CONCLUSION

Ocular manifestations are common in Stickler patients, but the comparison between studies was difficult because of inconsistencies in diagnostic and inclusion criteria by different studies. Sight-threatening complications such as retinal detachments are common but although prophylactic therapy is reported to be effective in retrospective studies, evidence from randomized trials is missing.

Best practice guidelines regarding diagnosis and management of patients with type II collagen disorders

PURPOSE

Skeletal dysplasias comprise a heterogeneous group of inherited disorders of development, growth, and maintenance of the human skeleton. Because of their relative rarity and wide phenotypic variability, patients should be accurately identified, uniformly assessed, and managed by clinicians who are aware of their potential complications and possess the knowledge and resources to treat them effectively. This study presents expert guidelines developed to improve the diagnosis and management of patients with type II collagen skeletal disorders to optimize clinical outcomes.

METHODS

A panel of 11 multidisciplinary international experts in the field of skeletal dysplasia participated in a Delphi process, which comprised analysis of a thorough literature review with subsequent generation of 26 diagnosis and care recommendations, followed by two rounds of anonymous voting with an intervening face-to-face meeting. Those recommendations with more than 80% agreement were considered as consensual.

RESULTS

After the first voting round, consensus was reached to support 12 of 26 (46%) statements. After the panel discussion, the group reached consensus on 22 of 24 revised statements (92%).

CONCLUSIONS

Consensus-based, expert best practice guidelines developed as a standard of care to assist accurate diagnosis, minimize associated health risks, and improve clinical outcomes for patients with type II collagen skeletal dysplasias.

Targeted next‑generation sequencing identifies two novel COL2A1 gene mutations in Stickler syndrome with bilateral retinal detachment

Stickler syndrome is a group of inherited connective tissue disorders characterized by distinctive facial and ocular abnormalities, hearing loss and early‑onset arthritis. The aim of the present study was to investigate the genetic changes in two Chinese patients with Stickler syndrome, manifested as bilateral retinal detachment and peripheral retinal degeneration. Complete ophthalmic examinations, including best‑corrected visual acuity, slit‑lamp examination and fundus examination, were performed. Genomic DNA was extracted from leukocytes of the peripheral blood collected from the patients, their unaffected family members and 200 unrelated control subjects from the same population. Next‑generation sequencing of established genes associated with ocular disease was performed. A heterozygous collagen type II α1 chain (COL2A1) mutation c.1310G>C (p.R437P) in exon 21 was identified in Family 1 and a heterozygous COL2A1 mutation c.2302‑1G>A in intron 34 was identified in Family 2. The functional effects of the mutations were assessed by polymorphism phenotyping (PolyPhen) and sorting intolerant from tolerant (SIFT) analysis. The c.1310G>C mutation was predicted to damage protein structure and function, and the c.2302‑1G>A mutation was predicted to result in a splicing defect. The findings of the current study expand the established mutation spectrum of COL2A1, and may facilitate genetic counseling and development of therapeutic strategies for patients with Stickler syndrome.

Bilateral Asymmetric Rhegmatogenous Retinal Detachment in a Patient with Stickler Syndrome

Here we present the long-term anatomical and visual outcomes of bilateral asymmetric rhegmatogenous retinal detachment repair in a patient with Stickler syndrome. A 17-year-old girl presented with decreased visual acuity in both eyes for more than one year. Her best-corrected visual acuity (BCVA) was 0.1 in the right eye and 0.05 in the left eye. Slit-lamp anterior segment examination revealed subcapsular cataract in both eyes. Fundus examination showed bilateral rhegmatogenous retinal detachment, chronic retinal detachment accompanied by multiple retinal holes, tears and membranous fibrillary vitreous in the peripheral retina. Grade C2 proliferative vitreoretinopathy was observed in the left eye. Scleral buckling surgery was performed initially for both eyes. After the primary surgical procedure, retinal reattachment was achieved in the right eye and the left eye underwent phacoemulsification, intraocular lens implantation, pars plana vitrectomy (PPV), and silicone oil injection. After these surgical procedures retinal reattachment was achieved in the left eye. Silicone oil removal was performed six months after PPV surgery. After surgical treatment, BCVA was 0.6 in the right eye at the end of the 3.5-year follow-up period. After silicone oil removal, BCVA reached 0.2 in the left eye after 36 months of follow-up and retinal reattachment was achieved in both eyes. Scleral buckling surgery and PPV are effective and confidential methods for the treatment of chronic retinal detachment cases in Stickler syndrome.

A novel mutation in the COL2A1 gene in a patient with Stickler syndrome type 1: a case report and review of the literature

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.

CASE PRESENTATION

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.

Reduced penetrance in a large Caucasian pedigree with Stickler syndrome

BACKGROUND

In a four-generation Caucasian family variably diagnosed with autosomal dominant (AD) Stickler or Wagner disease, commercial gene screening failed to identify a mutation in COL2A1 or VCAN. We utilized linkage mapping and exome sequencing to identify the causal variant.

MATERIALS AND METHODS

Genomic DNA samples collected from 40 family members were analyzed. A whole-genome linkage scan was performed using Illumina HumanLinkage-24 BeadChip followed by two-point and multipoint linkage analyses using FASTLINK and MERLIN. Exome sequencing was performed on two affected individuals, followed by co-segregation analysis.

RESULTS

Parametric multipoint linkage analysis using an AD inheritance model demonstrated HLOD scores > 2.00 at chromosomes 1p36.13-1p36.11 and 12q12-12q14.1. SIMWALK multipoint analysis replicated the peak in chromosome 12q (peak LOD = 1.975). FASTLINK two-point analysis highlighted several clustered chromosome 12q SNPs with HLOD > 1.0. Exome sequencing revealed a novel nonsense mutation (c.115C>T, p.Gln39*) in exon 2 of COL2A1 that is expected to result in nonsense-mediated decay of the RNA transcript. This mutation co-segregated with all clinically affected individuals and seven individuals who were clinically unaffected.

CONCLUSIONS

The utility of combining traditional linkage mapping and exome sequencing is highlighted to identify gene mutations in large families displaying a Mendelian inheritance of disease. Historically, nonsense mutations in exon 2 of COL2A1 have been reported to cause a fully penetrant ocular-only Stickler phenotype with few or no systemic manifestations. We report a novel nonsense mutation in exon 2 of COL2A1 that displays incomplete penetrance and/or variable age of onset with extraocular manifestations.

Pierre Robin sequence: Management of respiratory and feeding complications during the first year of life in a tertiary referral centre

OBJECTIVES

To review early clinical manifestations of Pierre Robin sequence (PRS) and their management during the first year of life in the University Hospitals Leuven.

METHODS

Retrospective series of 48 patients with PRS born between 2001 and 2011 and treated at a tertiary referral hospital. Review of the current literature about management of respiratory and breathing difficulties in the early life of PRS patients.

RESULTS

Of our cleft palate patients 15.3% presented with PRS. A syndrome was diagnosed in 14.6%, associated anomalies without a syndromic diagnosis in 56.3% and isolated PRS in 29.2% of the cases. Mortality rate directly related to PRS was 2.1%. Respiratory difficulties were observed in 83.3% and feeding difficulties in 95.6% of the patients. Respiratory problems were addressed in a conservative way in 75%, in a non-surgical invasive way in 42.5% and in a surgical way in 12.5%. A statistically significant relationship between the association of a syndrome or other anomalies, and a higher need for resuscitation and invasive treatment were found (chi-square test, p-values=0.019 and 0.034). Feeding difficulties were managed conservatively in 91.3%, invasively in 80.4% and surgically in 15.2%.

CONCLUSIONS

PRS is frequently associated with other abnormalities or syndromes. Therefore routine screening for associated anomalies in neonates with PRS is recommendable. Respiratory and feeding complications are highly frequent and possibly severe, particularly in patients with associated anomalies or syndromes, and should be recognized and addressed appropriately in an early stage. There is a potential role for the nasopharyngeal airway in reducing the need for the more traditional surgical interventions for respiratory problems.

Recognizable syndromes in the newborn period

Making the diagnosis of genetic syndromes in the neonatal period can be challenging, as limited information concerning growth and development is available. The pattern of dysmorphic features and malformations is, therefore, correspondingly more important in syndrome recognition. The authors provide specific examples of the differences in the presentation for selected syndromes between the newborn period and later childhood. The purpose is to describe the variation in presentation that can occur with chronologic age and to aid in the early diagnosis of these conditions.

Stickler syndrome. Epidemiology of retinal detachment

OBJECTIVE

A review was performed on all patients with Stickler syndrome that had been treated in our Centre since it was diagnosed, in order to evaluate the risk of suffering a retinal detachment (RD).

METHODS

A total of 14 patients, diagnosed by clinical criteria, were included. The following variables were evaluated: age, gender, ocular background, follow-up, initial and final visual acuity (VA), optical prescription, prophylactic treatment, surgery and techniques performed. The risk age to suffer a RD, as well as cataracts, was determined by using the Kaplan-Meier survival curve analysis.

RESULTS

From a total of 5 men and 9 women, the median initial VA was 0.35, which was the same as the final VA. The median optical prescription was -9.5 D myopia. The median of follow-up was 7 years. Ocular background was 4 RD cases and 2 Lasik surgeries. The operations performed were 8 RD, 12 cataract, 2 glaucoma, 2 macular hole, and one endotropia. The median age of RD was 20 years and cataract 34 years. As regards surgical tecnique, 4 scleral buckle cases, and 4 scleral buckle+pars plana vitrectomy cases were formed. The prophylactic treatments performed were: one scleral buckle case, 4 endolaser photocoagulation, and one cryotherapy. Two of which presented with RD.

CONCLUSION

In the series presented, retinal detachment in Stickler syndrome mainly occurs in the second decade of life, with cataracts mainly developing in the fourth decade.