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Objectives: To characterize the natural history and possible mechanisms of hearing loss in Stickler syndrome (OMIM 108300; or hereditary progressive arthro-ophthalmopathy) and to determine if the auditory phenotype is a useful discriminating feature for the differential diagnosis of this group of disorders., Design: Multifamily study., Setting: Outpatient audiology and otolaryngology clinics at the Warren Grant Magnuson Clinical Center of the National Institutes of Health, Rockville, Md., Subjects: Forty-six affected individuals from 29 different families segregating Stickler syndrome., Interventions: Clinical audiologic and otolaryngological examinations were performed on all individuals, including pure-tone audiometry, speech audiometry, and middle ear immittance testing. Otoacoustic emissions, auditory brainstem response, infrared video electronystagmography, and temporal bone computed tomography were performed on a subset of participants., Results: The hearing loss was most often sensorineural in adults, and approximately 28 (60%) of the 46 adult patients had 2 or more thresholds greater than the corresponding 95th percentile values for an age-matched, otologically normal population. The hearing loss most often affected high frequencies (4000-8000 Hz) and was generally no more progressive than that due to age-related hearing loss. Type A(D) tympanograms (classification using the Jerger model), indicating hypermobile middle ear systems, were observed in 21 (46%) of the 46 affected individuals. Computed tomography of the temporal bones revealed no inner ear malformations in 19 affected individuals., Conclusions: The hypermobile middle ear systems observed in ears with normal-appearing tympanic membranes represent a novel finding for Stickler syndrome and are likely to be a useful diagnostic feature for this disorder. The overall sensorineural hearing loss in type I Stickler syndrome is typically mild and not significantly progressive. It is less severe than that reported for types II and III Stickler syndrome linked to COL11A2 (OMIM 120290) and COL11A1 (OMIM 120280) mutations, respectively, or the closely related Marshall syndrome. This difference will be a useful discriminatory feature in the differential diagnosis of this group of disorders.

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 proband, a French-Canadian white boy, presented with congenital sensory polyneuropathy, moderate to severe sensorineural hearing loss, infantile cataracts, nystagmus, esotropia, unusual facies, hypotonia, bilateral congenital hip dysplasia, delayed ossification of the femoral heads, scoliosis, short stature secondary to growth hormone deficiency, and developmental delay. His parents are consanguineous. His maternal first cousin, a 16-year-old girl, has congenital sensory polyneuropathy, infantile cataracts, unusual facies, scoliosis, short stature secondary to growth hormone deficiency, late-childhood-onset arthritis, and hypoglycemia. Reportedly, she has no hearing difficulties and has normal intelligence. Her parents are third cousins. These children appear to have a distinct variant of hereditary sensory and autonomic neuropathy with infantile cataracts, unusual facies, skeletal dysplasia, short stature secondary to growth hormone deficiency, and other features, with probable autosomal recessive inheritance.

We determined the clinical characteristics of cataract in 133 patients with the Stickler syndrome. Cataracts of various types or aphakia were found in 115 of 231 eyes (49.8%) studied. The most frequent and distinctive lesions, described as wedge and fleck cataracts, accounted for 40 of the 93 cataracts (43.0%) observed. These distinctive opacities may serve as a clinical marker for the Stickler syndrome and facilitate early diagnosis.

Norrie's disease is an x-linked recessive disorder characterized by progressive oculoacousticocerebral degeneration. The light and electron microscopic changes in the temporal bones, eyes, and brain of an affected 77-year-old man who suffered from bilateral profound sensorineural hearing loss, blindness, and mental retardation are described. The inner ears showed marked atrophy of the stria vascularis, severe degeneration of hair cells and cochlear neurons, and connective tissue proliferation in the spiral ganglion, osseous spiral lamina, and walls of the membranous vestibular labyrinth. The eyes showed detached retinae, dense proliferation of fibrillary glial cells in the retina and vitreous, severe atrophy of the optic nerves, and degenerative hyalinization of blood vessels. This case is the first published report of the histopathology of the inner ear in Norrie's disease.

We have evaluated a sister and brother with a similar pattern of malformations and death in early childhood associated with partial duplication chromosome 5p and possibly deletion of 9p. The father and the brother and several paternal relatives are carriers of the balanced translocation t(5;9) (p13;p22). The malformations which the two have in common are: prominent forehead, flat nasal bridge, long thin fingers, bilateral equinovarus deformity of the feet, diaphragmatic hernia and kidney malformations. The children died at ages 4 months and 27 months, the latter showing marked psychomotor retardation. The chromosome abnormalities, clinical history, and phenotypic features of our patients are similar to the case reported by Monteleone et al (1976). The findings in our patients and Monteleone et al. (1976) are not similar to those in other reported cases of partial and complete 5q duplications, perhaps because the others do not have partial deletion of 9p.

A one-year-old boy presented with findings of ocular colobomas and staphylomas in both eyes. He also had a single central incisor and growth failure. His mother had hyposmia. We think that the patient and his mother represent the mild end of the spectrum of autosomal dominant holoprosencephaly.

Tapetoretinal degeneration is not infrequently associated with other systemic abnormalities. The authors have examined an 11-year-old girl with severe pigmentary degeneration of the retina associated with severe musculoskeletal abnormalities, growth failure, recurrent respiratory problems, sensorineural hearing loss, and mental retardation. To the best of their knowledge, this constellation of features has not been described previously and probably represents a new clinical entity.

We have evaluated four individuals from two unrelated families with a similar multiple congenital anomalies/mental retardation (MCA/MR) syndrome due to partial duplication of chromosome 1q and possible deletion 18p. In both families the mothers and several relatives were carriers of the balanced translocation rcp t(1;18) (q42;p11). The features which the four have in common are relative macrocephaly, prominent forehead, micrognathia, and highly arched palate; three of the four individuals have short stature, scoliosis, kyphosis, hirsutism, camptodactyly, sacral dimple, repaired inguinal hernias, and eye abnormalities. Reproductive histories of five balanced translocation carriers in these families indicate that they have a high risk of spontaneous abortions and infants with multiple malformations.

An increased prevalence of mitral-valve prolapse occurs in several connective tissue dysplasias, including Marfan syndrome, Ehlers-Danlos syndrome, and pseudoxanthoma elasticum. We evaluated 57 patients diagnosed as having the Stickler syndrome for mitral-valve prolapse by auscultation and two-dimensional echocardiography. The diagnosis was made on the basis of craniofacial and musculoskeletal abnormalities, sensorineural hearing loss, eye defects, and a family history of Stickler syndrome. Twenty-six patients (45.6%) had mitral-valve prolapse, including 11 of 22 females (50.0%) and 15 of 35 males (42.9%). The age range of our study population was 4 to 60 years. Prevalence of mitral-valve prolapse did not increase with age. Nine patients (34.6% of those with mitral-valve prolapse) had the click-murmur syndrome; only one of them was symptomatic. Because of the growing list of complications associated with mitral-valve prolapse, all patients with Stickler syndrome should be evaluated by auscultation, electrocardiogram, and echocardiography. Those with mitral-valve prolapse should be advised to have periodic follow-up and to instruct physicians caring for them of their need for antibiotic prophylaxis with certain surgical procedures.

The Stickler syndrome is an autosomal dominant hereditary disorder of connective tissue with pleiotropic features including premature osteoarthropathy, mild spondyloepiphyseal dysplasia, vitreoretinal degeneration, and the Pierre-Robin sequence. Genetic linkage studies in two families with the Stickler syndrome have been performed using restriction fragment length polymorphisms associated with the structural gene for type II collagen, COL2A1. No recombinants between the Stickler phenotype and COL2A1 were observed. The total LOD score for linkage of the Stickler syndrome and COL2A1 at a recombination fraction (theta) of zero is 3.59. These findings suggest that, at least in some families, the mutation causing Stickler syndrome affects the structural locus for type II collagen.

Anterior and posterior segment findings were evaluated in 184 consecutive cases of stage 5 retinopathy of prematurity (ROP) (368 eyes). One hundred seventy patients had one or more examinations under anesthesia and 150 had open-sky vitrectomy (260 eyes) with or without additional surgery. Ocular findings were inspected and special attention was given to verify the morphology of the retinal detachment (RD) as predicted by ultrasonography. Immature iris and/or pupil, posteriorly or totally closed detachment funnels, vascularized epiretinal membranes, retinal folds, tractional retinoschisis, persistent hyaloid system, and subretinal blood and/or organization were the most significant indicators of bad prognosis. Evaluating stage 5 ROP eyes with these variables in mind is therefore essential.

Ten unrelated retinoblastoma patients were studied cytogenetically with high-resolution prophase banding; two had a deletion of chromosome 13, band q14. Neither of the two patients had any of the congenital defects usually associated with 13q14 deletions. In patient A, the deletion was found to be de novo. Patient B was found to be mosaic for the 13q14 deletion with 54% of the lymphocytes examined having the deletion. This study indicates that the 13q14 deletion may occur in a significant portion of all retinoblastoma cases. Esterase D activity and isozymes were studied also. The significance of findings will be discussed.

This is the first report to our knowledge of trisomy 21 in two members of a set of triplets. The two with Down syndrome are monozygous; the other triplet is not identical. These triplets were born to a 22-year-old woman in whose family there have been six sets of twins (four like-sex) since 1775. Neither parent has any chromosomal abnormality. Zygosity estimates in the triplets are derived from studies of red blood cell antigens and HLA typing. Twinning has been reported in association with many different chromosome abnormalities. It has been suggested that the incidence of Down syndrome among twins is significantly higher than among singletons. It seems likely that some families have a heritable predisposition to both twinning and chromosome abnormalities.

Norrie's disease, or congenital progressive oculo-acoustico-cerebral degeneration, is a rare X-linked recessive syndrome of retinal malformation, deafness, and mental retardation and/or deterioration. The natural history of the disorder in two families with five affected males, four living and one deceased, is described. The histopathology of two patients, one from each family, is reported. Differential diagnosis, treatment, and genetic counseling are discussed.

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.

A dysmorphic retarded fourteen-mont-old female with partial deletion of the long arm of chromosome 6 is presented. The breakpoint in 6q was in region 2, probably at band 5. Eight other infants with a deletion involving the long arm of chromosome 6, including five with a ring chromosome 6, have been reported. The affected individuals have in common microcephaly, micrognathia, hypotonia and psychomotor retardation, but do not appear to have a distinctive phenotype.

The ocular histopathologic findings in three patients with the Stickler syndrome from two families included the following: total retinal detachment with marked folding, disorganization of the retina, and a preretinal membrane. The progression of the fundus lesions was followed up in two patients during the course of 30 and 24 years. Many cases variously reported as Wagner's disease, familial retinal detachment, hyaloideoretinopathy with cleft palate, and the Pierre Robin syndrome probably were the Stickler syndrome.

The genes for MAO-A and MAO-B appear to be very close to the Norrie disease gene, on the basis of loss and/or disruption of the MAO genes and activities in atypical Norrie disease patients deleted for the DXS7 locus; linkage among the MAO genes, the Norrie disease gene, and the DXS7 locus; and mapping of all these loci to the chromosomal region Xp11. The present study provides evidence that the MAO genes are not disrupted in "classic" Norrie disease patients. Genomic DNA from these "nondeletion" Norrie disease patients did not show rearrangements at the MAOA or DXS7 loci. Normal levels of MAO-A activities, as well as normal amounts and size of the MAO-A mRNA, were observed in cultured skin fibroblasts from these patients, and MAO-B activity in their platelets was normal. Catecholamine metabolites evaluated in plasma and urine were in the control range. Thus, although some atypical Norrie disease patients lack both MAO-A and MAO-B activities, MAO does not appear to be an etiologic factor in classic Norrie disease.

Five cloned DNA segments within or adjacent to human chromosome band 13q14 were mapped by a combination of in situ hybridization and DNA dosage blotting. The DNA was isolated from human retinoblastoma patients with deletions varying in size and precise location. One of these deletions occurred in mosaic form, requiring T-cell cloning to obtain cells uniformly containing the deletion and useful for blotting. Regions of overlap between the intervals on chromosome #13 deduced for each probe from the two different mapping methods permitted a more precise location for each, from which a physical ordering of these five probes could be obtained. This ordered set of probes constitutes the start of a grid spanning band 13q14 of potential use in the diagnosis and understanding of human retinoblastoma.

Twenty-one Mut mutants were obtained from Escherichia coli B (B/UV) and K-12 (JC355) after treatment with mutagens. These Mut strains are characterized by rates of mutation to streptomycin resistance and T-phase resistance which are significantly higher than the parental (Mut(+)) rates. Mutator genes in 12 strains have been mapped at three locations on the E. coli chromosome: one close to the leu locus; five close to the purA locus; and six close to cysC. In addition, eight mutator strains derived from E. coli B/UV are still unmapped. Some effort was made to deduce the mode of action of the mutator genes. These isolates have been examined for possible defects in deoxyribonucleic acid repair mechanisms (dark repair of ultraviolet damage, host-cell reactivation, recombination ability, repair of mitomycin C damage). By using transductional analysis, it was found that the ultraviolet sensitivity of NTG119 and its mutator property results from two separate but closely linked mutations. PurA(+) transductants that receive mut from NTG119 or NTG35 are all more sensitive to mitomycin C than is the PurA recipient. Unless transduction selects for sensitivity, a probable interpretation is that defective repair of mitomycin C-induced damage is related to the mode of action of mut in these transductants and the donor. Abnormal purine synthesis may be involved in the mutability of some strains with cotransduction of the mutator properly and purA (100% cotransduction for NTG119). Three mutators are recombination-deficient and may have a defective step in recombination repair. One maps near three rec genes close to cysC.