1) Waardenburg PJ : A new syndrome combining developmental anomalies of the eyelids, eyebrows and nose root with pigmentary defects of the iris and head hair and with congenital deafness. Am J Hum Genet 3 : 195-253, 1951. 2) Read AP : Waardenburg syndrome. In : Scriver CR, Kaufman S, Eisensmith E, Woo SLC, Vogelstein B, Childs B (eds) : The metabolic and molecular bases of inherited Hill, NY, 2001, 6097-6116. disease, 8 ed. McGraw 3) Farrer LA, Grundfast KM, Amos J, Arnos KS, Asher JH Jr, et al : Waardenburg syndrome (WS) type I is caused by defects at multiple loci, one of which is near ALPP on chromosome 2 : first report of the WS consortium. Am J Hum Genet 50 : 902-913, 1992. 4) Tassabehji M, Read AP, Newton VE, Patton M, Gruss P, et al : Mutations in the PAX3 gene causing Waardenburg syndrome type 1 and type 2. Nat Genet 3 : 26-30, 1993. 6) Hageman MJ, Delleman JW : Heterogeneity in Warrdenburg syndrome. Am J Hum Genet 29 : 468-485, 1977. 8) Arias S : Genetic heterogeneity in the Warrdenburg syndrome. Birth Defects 7 : 87-101, 1971. 10) Liu XZ, Newton VE, Read AP : Waardenburg syndrome type II : phenotypic findings and diagnostic criteria. Am J Med Genet 55 : 95-100, 1995. 11) Newton VE : Clinical features of the Waardenburg syndromes. Adv Otorhinolaryngol 61: 201-208, 2002. 13) Newton V : Hearing loss and Warrdenburg's syndrome : Implications for genetic counseling. J Laryngol Otol 104 : 97-103, 1990. 14) Marcus RE : Vestibular function and additional

findings in Waardenburg syndrome. Acta Otolaryngol Suppl 229 : 7 `30, 1968. Summary Two CASES OF WAARDENBURG SYNDROME TYPE 1 : IMPLICATIONS FOR GENETIC COUNSELING Yuko Saitoh, MD Department of Pathology, Institute for Developmental Research, Aichi Human Service Center Rieko Tanaka, MD Department of Pediatrics, Japanese Red Cross Society, Wakayama Medical Center Takema Sakoda, MD Michio Hazama Department of Otolaryngology, Japanese Red Cross Society, Wakayama Medical Center Hiroko Funakoshi, MD et al Department of Sensory and Moror Organs, Division of Otolaryngology Head and Neck Surgery, Faculty of Medicine, Tottori University Waardenburg syndrome type 1, caused by a congenital ectodermal germ layer defect with an autosomal dominant pattern of inheritance and variable phenotypic expressivity, consists of 6 major characteristics : dystopia canthorum, broad nasal root, hypertrichosis of the medial eyebrow, heterochromia irides, white forelock, and congenital sensory hearing loss. These stigmata may be present in any combination and degree. We report two cases of Waardenburg syndrome type 1. The first case was a one-month old girl with unilateral deafness identified through early neonatal hearing screening. The second case was the child's father, who did not have any hearing loss. The degree of hearing loss is variable within and between families. The implications of this finding for genetic counseling in families with this syndrome are discussed. Key words : Waardenburg syndrome type 1, hearing loss, genetic counseling