The Stickler syndrome (hereditary arthro-ophthalmopathy)

Thoracolumbar spinal abnormalities in Stickler syndrome

STUDY DESIGN

Retrospective review of clinical and radiographic records of patients with Stickler syndrome.

OBJECTIVES

To describe thoracolumbar spinal abnormalities and their correlation with age and back pain among patients with Stickler syndrome.

SUMMARY OF BACKGROUND DATA

Stickler syndrome (hereditary arthro-ophthalmopathy) is an autosomal dominant connective tissue disorder characterized by skeletal, ocular, oral-facial, cardiac, and auditory manifestations. Prevalence is approximately 1 in 10,000 (similar to that of Marfan syndrome). No one has investigated spinal abnormalities in a large series of patients.

METHODS

A single-center evaluation of 53 patients from 24 families with Stickler syndrome (age range, 1-70 years) in a multidisciplinary genetics clinic. Thoracolumbar radiographs were analyzed for spinal abnormalities and correlation with age and back pain.

RESULTS

Thirty-four percent of patients had scoliosis, 74% endplate abnormalities, 64% Schmorl's nodes, 43% platyspondylia, and 43% Scheuermann-like kyphosis. Sixty-seven percent of patients and 85% of adults reported chronic back pain. Endplate abnormalities and Schmorl's nodes were associated with adult age; endplate abnormalities, Schmorl's nodes, and adult age were associated with back pain. Only one adult patient was free of spinal abnormalities.

CONCLUSIONS

Spinal abnormalities are nearly uniformly observed in Stickler syndrome, progress with age, and are associated with back pain. Although common, scoliosis is generally self-limited (only one patient needed surgical treatment). Correct diagnosis of this syndrome facilitates early identification and management of other potentially severe systemic manifestations and genetic counseling for affected families. Moreover, recognition of Stickler syndrome allows accurate prognosis for skeletal abnormalities and anticipation of potential surgical complications.

Rapid determination of COL2A1 mutations in individuals with Stickler syndrome: analysis of potential premature termination codons

Stickler syndrome is one of the milder phenotypes resulting from mutations in the gene that encodes type-II collagen, COL2A1. All COL2A1 mutations known to cause Stickler syndrome result in the formation of a premature termination codon within the type-II collagen gene. COL2A1 has 10 in-frame CGA codons, which can mutate to TGA STOP codons via a methylation-deamination mechanism. We have analyzed these sites in genomic DNA from a panel of 40 Stickler syndrome patients to test the hypothesis that mutations that cause Stickler syndrome preferentially occur at these bases. Polymerase chain reaction (PCR) amplification of genomic DNA containing each of the in-frame CGA codons was done by one of two methods: either using primers that amplify DNA that includes the CGA codon, or using allele-specific primers that either amplify normal sequence containing a CGA codon or amplify a mutant sequence containing a TGA codon. Analysis of PCR products by restriction endonuclease digestion or sequencing demonstrated the presence of a normal or mutated codon. TGA mutations were identified in eight patients, at five of the 10 in-frame CGA codons. The identification of these mutations in eight of 40 patients demonstrates that these sites are common sites for mutations in individuals with Stickler syndrome and, we propose, should be analyzed as a first step in the search for mutations that result in this disorder.

The spinal manifestations of Stickler's syndrome

STUDY DESIGN

A review of current knowledge, clinical publications, and recent concepts of the causes of Stickler's syndrome was correlated with a clinical review of the condition at the Children's Hospital of Eastern Ontario, Canada.

OBJECTIVES

To acquaint orthopedic spine surgeons with the natural history, associated anomalies, and high incidence of spinal deformity and scoliosis in children with Stickler's syndrome.

SUMMARY OF BACKGROUND DATA

Stickler's syndrome is a hereditary, progressive arthro-ophthalmopathy with an autosomal dominant inheritance pattern. The estimated incidence is 1 in 10,000 people, which is slightly more common than Marfan syndrome.

METHODS

The experience with Stickler's syndrome was reviewed in seven children, 2-15 years of age, with particular attention to the spinal abnormalities secondary to the connective tissue dysplasia.

RESULTS

Six of the children had kyphosis or scoliosis, and four had wedging or flattening of the vertebrae or platyspondylia. In general, the spinal changes became more prominent in the older children with Stickler's syndrome, with the spinal vertebrae affected by the generalized epiphyseal dysplasia. The treatment of scoliosis and kyphosis is no different in children with Stickler's syndrome. The most difficult aspect is in diagnosing the condition.

CONCLUSIONS

The importance of recognizing the syndrome is to allow for the investigation and treatment of the many other associated connective tissue disorders associated with Stickler's syndrome, such as the high incidence of retinal detachment, mitral valve prolapse, and mandibular hypoplasia that may result in problems with anesthesia should the spine require surgical stabilization.

Hereditary vitreopathy

Heterogeneity has long been recognised within the spectrum of inherited vitreo-retinal disease but the extent of the variation has been less easy to quantify. This has been compounded by the small size and numbers of pedigrees available for the study, and the phenotypic variation both within and between pedigrees. Formation abnormalities in the vitreous architecture have, in the past, been eclipsed by classifications based on general skeletal and morphological differences. Stickler syndrome is the commonest disorder within the spectrum of hereditary vitreous abnormalities and many of the recent published advances relate to this. Stickler syndrome has been subclassified on the basis of vitreo-retinal phenotype: type 1 families with a characteristic congenital vitreous anomaly show linkage without recombination to markers at the COL2A1 locus; type 2 families with different congenital vitreo-retinal phenotypes are not linked to COL2A1. A recent report identifies the COL11A2 mutation in a Dutch pedigree with systemic features of Stickler syndrome but without ocular involvement. Others have implicated COL11A1 in a type 2 Stickler syndrome pedigree with ocular abnormalities. Both COL11A1 and COL11A2 are expressed in cartilage, but on the basis of studies of bovine vitreous it is likely that only the alpha 1(XI) chain encoded by COL11A1 is present in vitreous. This would be consistent with the hypothesis that mutations in the genes encoding collagen XI can give rise to manifestations of Stickler syndrome, but of these, only mutations in COL11A1 will give the full syndrome including the vitreo-retinal features.

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.

Central nervous system malformations in the CHARGE association

Of 144 patients with the CHARGE association (literature 136, new patients 8), 47 (33%) had either a postmortem examination (30) or computerized axial tomography scan (17) of the head. Twenty-six of 47 (55%) had definite central nervous system (CNS) malformations; arhinencephaly, with or without other defects (11), holoprosencephaly (2), holoprosencephaly with arhinencephaly (1), other forebrain defects (3), hindbrain defects (3), or other defects (6). The presence of CNS malformation was most strongly associated with choanal atresia. This review demonstrates a predominance of forebrain anomalies, particularly arhinencephaly and holoprosencephaly, which may provide a clue to the mechanism of abnormal morphogenesis involved in CHARGE association.

Ocular findings in CHARGE syndrome. Six case reports and a review

CHARGE syndrome is a group of nonrandomly occurring congenital anomalies which may present to the ophthalmologist, because coloboma is one of the major findings. In a series of 54 patients with ocular colobomata, 6 (11%) were found to meet the criteria for CHARGE syndrome. The mnemonic CHARGE stands for the major features of this syndrome: Coloboma, Heart defects, Atresia of the choanae, Retarded growth and development, Genital hypoplasia, and Ear anomalies and/or hearing loss. No specific etiology is known, but autosomal dominant, autosomal recessive, and X-linked recessive forms have been suggested by familial reports. The authors describe six patients with CHARGE syndrome, including the second reported case occurring in monozygotic twins. Other syndromes, chromosomal defects, and effects of teratogens may have similar clinical presentations. Though our prevalence may be skewed by our referral setting, the frequency of occurrence of this syndrome is certainly high enough that ophthalmologists should be familiar with it. Evaluation for associated defects should be carried out and referral for genetic evaluation undertaken when appropriate.

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.

Congenital anomalies in patients with choanal atresia: CHARGE-association

Six patients with both choanal atresia (ChA) and additional malformations are described and another 110 cases with this combination reviewed from the literature. Our study of these cases supports the existence of the CHARGE-association (Coloboma, Heart Disease, Atresia of choanae, Retarded mental development and growth, Genital hypoplasia, Ear anomalies and deafness). Our findings suggest the inclusion of orofacial clefts and oesophageal atresia among the main symptoms of this association. A certain degree of facial dysmorphism (low set, dysplastic ears, retrogenia, antimongoloid slant of palpebral fissures and anteverted nares) was observed in each of our cases. Infants with the bilateral type of ChA plus cardiac defects and those with ChA plus renal malformations have a high mortality rate. The aetiology of the association is not clear. The recurrence risk may be low.

Coloboma, congenital heart disease, and choanal atresia with multiple anomalies: CHARGE association

We report 21 patients with choanal atresia or ocular coloboma or both who have certain other associated anomalies, including congenital heart disease, postnatal growth deficiency, mental retardation and/or CNS anomalies, microphallus and cryptorchidism, and ear anomalies and/or deafness. Facial palsy, micrognathia, cleft palate, and swallowing difficulties were also common. It has not been possible to define a single etiology or a syndrome in these patients. We propose the mnemonic CHARGE (C-coloboma, H-heart disease, A-atresia choanae, R-retarded growth and retarded development and/or CNS anomalies, G-genital hypoplasia, and E-ear anomalies and/or deafness) to describe the features of this association.

Ocular coloboma

Ocular coloboma is common malformation which includes a spectrum of anomalies that ranges from iris coloboma to clinical anophthalmos. Coloboma is etiologically heterogeneous. As an isolated defect, it is usually inherited as an autosomal dominant disorder, although autosomal recessive inheritance also occurs. Patients with multiple malformations and coloboma may have a recognized malformation syndrome of unknown etiology, a single gene disorder, or chromosomal abnormality. Prognosis and recurrence risk can be determined only after complete evaluation of the patient and other family members.

Choanal atresia and associated multiple anomalies

Seventeen unrelated patients with multiple anomalies of unknown etiology were identified by the presence of choanal atresia. A regularly recurring pattern of associated features involving mental retardation, postnatal growth deficiency, hypogenitalism (males), small ears, cardiac defects, micrognathia, postnatal microcephaly, and ocular coloboma was identified. Choanal atresia when accompanied by multiple anomalies of unknown etiology has a serious prognosis with a predictable pattern of associated defects.