The Wagner-Stickler syndrome complex

Clinical variability of Stickler syndrome: role of exon 2 of the collagen COL2A1 gene

Stickler syndrome (progressive arthro-ophthalmopathy) is a genetically heterogeneous disorder resulting from mutations in at least three collagen genes. The most common disease-causing gene is COL2A1, a 54-exon-containing gene coding for type II collagen. At least 17 different mutations causing Stickler syndrome have been reported in this gene. Phenotypically, it is also a variably expressed disorder in which most patients present with a wide range of eye and extraocular manifestations including auditory, skeletal, and orofacial manifestations. Some patients, however, present without clinically apparent systemic findings. This observation has led to difficulty distinguishing this Stickler phenotype from other hereditary vitreoretinal degenerations, such as Wagner syndrome and Snowflake vitreoretinal degeneration. In this regard, review of the literature indicates type II collagen exists in two forms resulting from alternative splicing of exon 2 of the COL2A1 gene. One form, designated as type IIB (short form), is preferentially expressed in adult cartilage tissue. The other form, designated as type IIA (long form), is preferentially expressed in the vitreous body of the eye. Because of this selective tissue expression, mutations in exon 2 of the COL2A1 gene have been hypothesized to produce this Stickler syndrome phenotype with minimal or absent extraocular findings. We review the evidence for families with exon 2 mutations of the collagen COL2A1 gene presenting in a distinct manner from families with mutations in the remaining 53 exons, as well as other hereditary vitreoretinal degenerations without significant systemic manifestations.

Hereditary vitreoretinal dystrophy associated with peripheral neuropathy

Autosomal dominant inherited vitreoretinal dystrophy has been reported to occur as isolated ocular disease (Wagner's disease) or in combination with systemic manifestations (e.g., Stickler's syndrome). We examined five members of one family (three generations) and found vitreoretinal dystrophy and non-ocular signs in a mother and her two children. In the mother we also observed tractional detachment of the macula. In addition to routine ophthalmological examinations, we performed electrophysiological tests (ERG, EOG), adaptometry and magnetic resonance imaging of the head. Neurological examination revealed peripheral neuropathy in the mother and her children. We had no evidence that the neuropathy had a toxic or metabolic origin, and other genetically determined neuropathies were unlikely based on the clinical picture, MRI, and laboratory tests. Therefore, the neuropathy might be either a hitherto unrecognized feature of a variant of Stickler's syndrome or part of a yet unclassified hereditary vitreoretinal dystrophy with systemic involvement.

Marshall syndrome

We report on a mother and daughter with Marshall syndrome, with the Robin sequence present in the daughter. Results of our efforts to link this syndrome to a defect in type II collagen are reported. We compare and contrast Marshall syndrome with the Stickler syndrome, and propose that enough phenotypic overlap exists to suggest that they are probably allelic expressions of the same locus.

Managing the cleft lip and palate patient

We have attempted to elucidate, first through an examination of the basic science of clefting and then through a description of the roles of the various members of the cleft palate team, an understanding of the multiplicity of problems faced by this heterogeneous group of children with cleft lip or palate. With an incidence of cleft of 1 in 700 births, all practicing pediatricians will at some time be faced with a patient with a cleft. Pediatric management begins in the hospital nursery by ruling out possible associated anomalies (e.g., congenital heart disease or urinary tract) or syndromes. At the same time, cleft palate nursers may be needed to overcome feeding problems. Simultaneously, counseling for the family begins with a positive attitude toward outcome and an initial explanation of the schedule of corrective procedures, i.e., lip repair at 3 months of age and palate repair at about 1 year. The counseling should incorporate an understanding of the cause of clefting, both its genetics and teratogenetics, and then proceed to noting the actual recurrence risks of 1% for a new cleft and 16% if there is a positive family history in a first-degree relative. The recurrence risks in recognized syndromes may follow mendelian patterns. Later, the pediatrician can help the family deal with multiple ear infections and the likely need for tympanostomy tubes, anticipating the need for tubes in a way that might facilitate placement at the time of anesthesia for the lip or the palate repairs. An understanding of the speech and language difficulties that may be encountered in later infancy may relieve parental anxiety. Later, after palate repair, knowledge of velopharyngeal incompetence may avert premature hypernasal speech problems caused by adenoidectomy, which should be avoided if at all possible. The pediatrician needs to be aware of the tooth malformations that accompany clefting of the alveolus as well as the increased susceptibility to caries, so that the family may be directed to early intervention by the pediatric dentist. With support by pediatrics of the efforts of pediatric dentistry, the child is then in optimal condition for orthodontics. Continually keeping the child's emotional adjustment in mind, the pediatrician can encourage the child and family, knowing that with palatal expansion techniques plus possible bone graft surgery to the cleft alveolus at about 9 years of age, the child may be orthodontically corrected to very near normal.(ABSTRACT TRUNCATED AT 400 WORDS)

Otolaryngological manifestations of the Stickler syndrome

The Stickler syndrome is a dominantly inherited, connective tissue disorder associated with retinal detachments, joint and skeletal abnormalities, and characteristic facies. We wished to evaluate patients with this disorder to ascertain the frequency of otolaryngological manifestations. Fourteen patients, 4-17 years of age, were evaluated when admitted for retinal detachment. Findings included: midface hypoplasia in all patients; mandibular hypoplasia in 11 patients; palatal anomalies in 10 patients (frank cleft in 6, submucous cleft in two, highly arched palate in two); and hearing loss in 6 patients (mixed loss in 3, sensorineural loss in 3). Hearing loss appeared more commonly in the higher frequencies; no apparent correlation was found between the presence of hearing loss and orofacial anomalies. Our experience suggests that the Stickler syndrome is not rare. Craniofacial dysmorphic features and otologic findings are sufficiently frequent to warrant otolaryngological evaluation.

Wagner's vitreoretinal degeneration with generalized epiphyseal dysplasia

Wagner's vitreoretinal degeneration, midline facial defects and a moderate generalized epiphyseal dysplasia defined radiologically were encountered in a boy and his father. The familial nature of the condition and its autosomal dominant inheritance are described. Suggestions are made that patients said to have Wagner's disease differ in no way radiologically from cases diagnosed as having Stickler's syndrome.