G. D'Alessandro, L. Armuzzi, G. Cocchi, G. Piana and fibrosis of the seminiferous tubules and elevated urinary gonadotrophins [Bojesen and Gravholt, 2007]. Department of Dental Science, Dental School, This means that these subjects do not produce enough Alma Mater Studiorum, University of Bologna, Bologna, Italy of the testosterone hormone before birth and during puberty; as a consequence during puberty, the normal e-mail: [email protected] male sexual characteristics do not develop fully. Affected males may exhibit psychosocial problems and minor developmental and learning disabilities, including delayed speech and language acquisition. Eruption delay However, a less distinct phenotype has been described. in a 47 XXY male: is an underdiagnosed condition; only 25% of the expected affected patients are a case report diagnosed, and of these only a minority are diagnosed before puberty [Hata et al., 2001]. Patients with Klinefelter syndrome should be treated with lifelong testosterone supplementation starting at puberty, abstract to prevent the long-term deleterious consequences of hypogonadism and to secure proper masculine Background The 47,XXY syndrome, or Klinefelter development of sexual characteristics, muscle bulk and syndrome, though it is a rare occurrence, it is the bone structure [Bojesen and Gravholt, 2007]. most common sex choromosome disorder affecting Evidence accumulated over the last four decades male subjects. This syndrome is underdiagnosed and supports the role of both X and Y chromosomes, seldomly before puberty. In this case, diagnosis was independently of secondary hormonal influences, made before birth, through chorion villus sampling. on growth and development of dental structures Case report A 16 month-old Italian male with [Garn and Rohman, 1962]. In general, the results of 47 XXY syndrome showed the absence of primary measurements of enamel and dentine layers thickness teeth, with a delay of about 8-10 months, whereas in individuals with various types of during the first 15 months of life the auxological abnormalities indicate that the development has been normal both in weight and primarily influences enamel thickness, whereas the Y height (about 50th percentile). We assumed that chromosome promotes both enamel deposition and this delay may be linked with Klinefelter syndrome, dentine growth [Alvesalo 1981, 1985]. as sexual chromosomes play an important role in the Cephalometric investigation reveals reduced calvarial dental development. size, reduced cranial base angle, and gonial angle wider than normal. Both maxillary and mandibular tend to occur [Ingerslev and Kreiborg, Keywords Dental eruption delay; Klinefelter 1978]. In addition, various dental features have been syndrome; Primary dentition. observed, including taurodontism, [Stewart, 1974; Jaspers and Witkop 1980] congenital absence of permanent teeth [Stewart, 1974], shovel incisors [Gardener and Girgis 1978] and increased permanent Introduction tooth size [Townsend and Alvesalo, 1985].

Klinefelter syndrome is the most commonly occurring sex-chromosome disorder. It is characterised by Case report the presence of one or more extra X chromosomes. Several X- variants exist, including 47 XXY, A 15 month-old Italian male was referred to the 48 XXYY, 48 XXXY, and 49 XXXXY [Hunter et al., Department of Special Care, School of Dentistry of 2003] but the 47 XXY is the most prevalent, Bologna University. occurring in approximately 80% of the cases [Gorlin, The Chorion Villus Sampling (CVS) that had been 1977]. The birth prevalence of chromatin-positive carried out at the 12th week of gestation revealed a males is approximately 2:1000. male karyotype 47 XXY, consistent with Klinefelter The “classical” Klinefelter syndrome is associated with syndrome. From the familiar medical history we learned the 47,XXY karyotype and is characterised by narrow that the mother had previously had two , shoulders, broad hips, sparse body hair, at at the first month and at the 23th week of gestation late puberty, hypogonadism (small testes, azoospermia/ because of chorioamnionitis. oligospermia), androgen deficiency, hyalinization The child was normally delivered at 36 weeks; birth

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cm 56 54 52 CRANICAL 50 CIRCUMFERENCE 48 46 104 44 42 102 40 104 38 98 36 94 34 90 32 86 30 82 28 17 HEIGHT 78 26 16 74 fig. 2 The maxillary arch. 24 15 70 66 22 14 62 20 13 58 12 the auxological development of the child is otherwise 54 11 50 normal (Fig. 1). In addition there are not changes in 10 46 9 other organs of ectodermal derivation. WEIGHT 42 8 38 Though there is no evidence in literature that 7 34 eruption delay of primary teeth is a typical Klinefelter 6 30 5 syndrome feature, we suppose it may be linked with 26 4 cm this syndrome because sexual chromosomes play an 3 important role in the dental development. 2 1 Further studies are needed to investigate the relations 0 between the number of sexual chromosomes and kg 0 1 2 3 6 9 1 2 3 dental anomalies. fig. 1 Pediatric growth chart percentiles. Acknowledgements weight was 2,920 g and height 50 cm. Immediately after birth he was enrolled in a follow-up program at We would like to thank the Fondazione del Monte di the Paediatric Department of the Sant’Orsola-Malpighi Bologna e Ravenna for the support. University Hospital of Bologna, Italy, in order to perform regular auxological evaluations. New karyotype analysis confirmed the diagnosis References of Klinefelter syndrome. The abdominal ultrasound was normal,while cerebral ultrasound showed a mild › Alvesalo L, Tammisalo E. Enamel thickness in 45,X females’ permanent enlargement of LLVV and of the interhemisphere space. teeth. Am J Hum Genet 1981: 33: 464–469. › Alvesalo L. The , Part B. Clinical Aspects. Ed. Sandberg During the first 15 months of life the child exhibited AA (ed). New York 1985; 277–300. a good auxological development, both in weight and › Bojesen A, Gravholt CH. Klinefelter syndrome in clinical practice. Nat in height, with values in the 50th percentile (Fig. 1). Clin Pract Urol 2007: 4: 192–204. His clinical conditions are good and the neuromotor › Gardener DG, Girgis SS. Taurodontism, shovel-shaped incisors and the Klinefelter syndrome. J Canad Dent Assoc 1978; 8: 372–373. development is age-appropriate as well. He underwent › Garn SM, Rohman CG. X-linked inheritance of developmental timing in vitamin D implementation. man. Nature 1962; 196: 695–696. A clinical evaluation of the baby mouth revealed the › Gorlin RJ. New Chromosomal Syndromes. Ed. Yunis JJ, New York1977; total absence of primary dentition at the age of 16 59–117. › Hata S, Maruyama Y, Fujita Y, Mayanagi H. The dentofacial manifestations months (Fig. 2). of XXXXY syndrome: a case report. Int J Paediatr Dent 2001; 11:138-42. › Hunter ML, Collard MM, Razavi T, Hunter B. Increased primary tooth size in a 47,XXY male: a first case report. Int J Paediatr Dent 2003; 13: 271- Discussion 3. › Ingerslev CH, Kreiborg S. Craniofacial morphology in Klinefelter syndrome: roentgencephalometric investigation. Cleft Palat J 1978; 15: 100–108. The child exhibited a severe delay in dental eruption › Jaspers MT, Witkop CJ. Taurodontism, an isolated trait associated with of the primary teeth. Considering that the common syndromes and X-Chromosome aneuploidy. Am J Hum Genet 1980; 32: timing of eruption of central lower primary incisors is 396–413. › Stewart RE. Taurodontism in X–Chromosome aneuploid syndromes. Clin around 6-8 months, we observed a delay of about 8-10 Genet 1974; 6: 431–344. months. The eruption delay of primary mandibular › Townsend GC, Alvesalo L. The size of permanent teeth in Klinefelter incisors is an important clinical information because (47,XXY) syndrome in man. Arch Oral Biol 1985; 30: 83–84.

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