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Delayed-Onset Infantile Cataracts in a Case of Treacher Collins Syndrome
Arch Ophthalmol. 2004;122:1721-1722.
Treacher Collins syndrome (TCS), variably known as mandibulofacial dysostosis and Franceschetti-Klein-Zwahlen syndrome, is one of a number of congenital craniofacial abnormalities characterized by malformation of the derivatives of the first and second branchial arches. Though first described by Berry1 in 1889, the definition of the syndrome underwent further revision and classification by Franceschetti and Klein in 1949.2
The major features of the complete syndrome include bilateral hypoplasia of the mandible and zygoma, antimongoloid slanting of the palpebral fissures, micrognathia, beaked nose, malformed ears, and conduction deafness. Colobomata of the lateral lower eyelids are frequently seen, and for this reason, ophthalmologists are often consulted as part of the multidisciplinary team serving these patients. Other ocular findings, such as cataract, microphthalmos, and atresia of the lacrimal canals, are seen much less frequently.3
Although cataract has been reported in the literature as an infrequent feature of TCS, the time of onset and morphological features of such cataracts have not been previously described. We present a case of TCS notable for delayed onset of bilateral cataracts that developed after the first year of life.
Report of a Case
A 1-month-old girl was referred for evaluation of abnormal eyelids. She was a healthy, full-term, 2400-g infant, the first child born to a healthy 20-year-old mother who had no complications during pregnancy. At birth, notches of the lower eyelid were noted, and she was referred for evaluation. There was no family history of ocular disease or congenital syndromes. On examination, she was found to have bilateral lower eyelid colobomas involving the lateral third of the inferior lids (Figure 1). There were no periocular dermoids, no corneal limbal dermoids, no cataracts, and no optic nerve hypoplasia or ocular colobomas. The remainder of the ophtal- mic examination was unremarkable. She was also found to have malar hypoplasia. Given this facial appearance, the diagnosis of TCS was considered. The patient was evaluated by the Department of Medical Genetics, which confirmed this diagnosis. The child did well until 13 months of age when the parents began to notice cloudiness in the pupils of both eyes. On ophthalmic examination, she was found to have bilateral nuclear cataracts precluding view of the posterior pole in each eye (Figure 2). There was a small rim of clear cortex peripherally. Nys tagmus was not present. The patient underwent bilateral extracapsular cataract extraction with posterior chamber lens implantation without complication.
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Figure 1. On examination, the patient was found to have bilateral lower eyelid colobomas involving the lateral third of the inferior lids.
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Figure 2. On ophthalmic examination, the patient was found to have bilateral nuclear cataracts precluding view of the posterior pole in each eye.
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Comment
Treacher Collins syndrome is a congenital craniofacial abnormality that affects approximately 1 in 50 000 live births. It is transmitted by autosomal dominant inheritance with high penetrance and variable expressivity, though approximately 60% of cases occur with no family history and are thought to arise by de novo mutation.
The pathogenesis of TCS was initially thought to be due to defective ossification of the facial bones. However, the common derivation of the affected tissues from the first and second branchial arches led to speculation that defects in neural crest cell migration might be responsible.4 More recently, it has been suggested that premature cell death in the ectodermal placodes of the first and second branchial arches, rather than impaired migration of neural crest cells, may instead be the pathogenetic mechanism.5
The gene responsible for TCS has recently been cloned, and a protein product has been identified with homology to a family of nucleolar-cytoplasmic transport proteins.6 Almost all mutations identified in TCS result in premature termination of the protein product, suggesting that the pathogenetic effects result from haploinsufficiency of the gene product during embryogenesis. The precise function of this protein product and its role in TCS pathogenesis remain unknown. As a result of this research, a genetic test for prenatal diagnosis in affected families is now available.
Of note, the prevalence of cataracts is variable in other craniofacial syndromes involving malformation of the first and second branchial arches. They are seen very frequently in Hallerman-Streiff syndrome, occasionally in Pierre Robin syndrome, and are absent in Goldenhar syndrome.7
Though the literature refers to cataract as an infrequent ophthalmic finding in TCS, no specific caseswith cataract could be identified. There were no cataracts mentioned in 2 recent case series that examined the ocular findings in 14 and 24 patients with TCS, respectively.8-9
To our knowledge, this is the first reported case of delayed-onset infantile cataracts in TCS. It is significant because this child displayed no signs of cataract at birth or at 10 months of age but developed bilateral, visually significant cataracts by 13 months of age. The possibility that delayed-onset cataracts can develop rapidly in infants with TCS suggests that more frequent ophthalmologic follow-up and detailed anticipatory guidance to parents are warranted to prevent the possibility of undetected cataracts leading to irreversible amblyopia.
AUTHOR INFORMATION
Correspondence: Dr Fredrick, Department of Ophthalmology, University of California, San Francisco, 10 Koret Way, Box 0730, San Francisco, CA 94143-0730 (dfred{at}itsa.ucsf.edu).
Financial Disclosure: None.
Jesse B. Biebesheimer, BS;
Douglas R. Fredrick, MD
REFERENCES
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1. Berry GA. Two case reports. Royal London Ophthal Hosp Rep. 1889;12:255.
2. Franceschetti A, Klein D. The mandibulo-facial dysostosis: a new hereditary syndrome. Acta Ophthalmol (Copenh). 1949;27:143-224.
3. Hurwitz P. Mandibulofacial dysostosis. Arch Ophthalmol. 1954;51:69-74.
4. Poswillo D. The pathogenesis of the Treacher Collins syndrome. Br J Oral Surg. 1975;13:1-26.
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5. Sulik KK, Johnston MC, Smiley SJ, Speight HS, Jarvis BE. Mandibulofacial dysostosis (Treacher Collins syndrome): a new proposal for its pathogenesis. Am J Med Genet. 1987;27:359-372.
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6. Dixon J, Hovanes K, Shiang R, Dixon MJ. Sequence analysis, identification of evolutionary conserved motifs and expression analysis of murine tcof1 provide further evidence for a potential function for the gene and its human homologue, TCOF1. Hum Mol Genet. 1997;6:727-737.
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7. Feingold M, Gellis SS. Ocular abnormalities associated with first and second arch syndromes. Surv Ophthalmol. 1969;14:30-42.
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8. Wang FM, Millman AL, Sidoti PA, Goldberg RB. Ocular findings in Treacher Collins syndrome. Am J Ophthalmol. 1990;110:280-286.
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9. Hertle RW, Ziylan S, Katowitz JA. Ophthalmic features and visual prognosis in the Treacher-Collins syndrome. Br J Ophthalmol. 1993;77:642-645.
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