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Kabuki syndrome was named as such by Japanese authors because of the strikingly unusual facies of patients, reminiscent of the make-up used in the Kabuki traditional Japanese theater. First described in Japanese patients, this syndrome has been now reported in about 100 infants, from all regions of the world. Besides their facial appearance, affected children have mental retardation and postnatal progressive growth retardation as cardinal signs. Most children with Kabuki have a mild to moderate intellectual disability. A few, though they may need assistance with speech and fine motor skills, can follow the regular curriculum in school. Many babies gain weight slowly and may be labeled "failure-to-thrive infants". The majority of children will fall in the lower percentile for growth. A few of them require growth hormone therapy. The facial characteristics include lower palpebral eversion, long palpebral fissures, arched eyebrows, long and thick eyelashes, blue sclerae, depressed nasal tip, cleft lip/palate or high-arched palate, dysmorphic prominent ears with preauricular fistula, abnormal dentition: teeth are usually wide-spaced and irregular. There may be often a few missing primary and/or adult teeth. Most dental problems are easily corrected. About 50% of the children with Kabuki have heart defects, mostly aortic coarctation or septal defects. Skeletal abnormalities are unspecific, but often are represented by short 5th finger with clinodactyly, scoliosis, dislocation of hip and/or patella. Dermatoglyphic anomalies may be useful for diagnosis : finger tip pads, increase in ulnar loops, absence of digital triradius c, absence of digital triradius d, increase of hypothenar loops. Two thirds of patients have neurological deficiency: hypotonia, feeding problems, seizures, microcephaly, visual anomalies like nystagmus or strabismus. Early intervention is important in this case. They often have low muscle tone, which affects both fine and gross motor activities, and joint laxity. Physiotherapy and physical activity are important to strengthen the muscles. A few children present with obesity in adolescence with no obvious endocrinological explanation. Over 50% of persons with Kabuki experience hearing loss. In most cases it is a sensorineural (nerve type) hearing loss but in some cases, however, conductive hearing loss was noted. It is believed to be due to an abnormality of the ear bones. Recurrent otites are frequent too in these infants, and may be responsible for hearing loss as well. All forms can be treated by surgery or/and hearing aids. Because speech delay may result from hearing loss, it is critically important that a child`s hearing be frequently monitored from an early age. Numerous other anomalies have been reported in children with Kabuki syndrome: kidney or other urinary tract anomalies, wide set nipples, premature thelarche (breast development), precocious (early) puberty, diminished immunity, microcephaly, undescended testes and inguinal hernias in males, umbilical hernias, generalized hirsutism (hairiness) and vitiligo vulgaris (patches of depigmentation). Most cases are sporadic, but a few familial cases have been reported, suggesting an autosomal dominant inheritance with variable expressivity. The underlying genetic mechanism remains unknown. |