XXXXX SYNDROME

 

XXXXX SYNDROME

 

DEFINITION:

A disorder where affected females have five X chromosomes.

EPIDEMIOLOGY:

  • incidence: rare, about 25 cases reported
  • age of onset:
    • childhood
  • risk factors:
    • females only

PATHOGENESIS:

1. Background

  • first described by N. Kesaree and P.V. Wooley, J. Pediatr. 63: 1099 (1963).
  • also called Penta X Syndrome and Chromosome X, Poly-X

2. Pathogenesis

  • due to successive nondisjunctive meiotic divisions within the mother

CLINICAL FEATURES:

1. Dysmorphisms

  • hypertelorism
  • epicanthal folds
  • low nasal bridge
  • upward slanting palpebral fissures
  • low hairline
  • IUGR
  • failure to thrive
  • short stature
  • small hands with 5th finger clinodactyly
  • short neck

2. Neurological Manifestations

  • IQ ranges from 20-75
  • microcephaly

3. Endocrine Manifestations

  • absent sexual development
  • ovarian agenesis

4. Other Manifestations

1. Dental

  • taurodontism
  • enamal defects leading to premature loss of deciduous anterior teeth
  • dental malocclusion

2. Cardiovascular

  • congenital heart disease (Patent Ductus Arteriosus, Ventricular Septal Defect)

3. Musculoskeletal

  • equinovarus, overlapping toes, multiple joint dislocations (shoulder, elbow, hip, wrist, finger), radio-ulnar synostosis

4. Facial Features

  • colobomata of the iris
  • low-set ears, preauricular tags, macroglossia, micrognathia, cleft palate

5. Renal

  • horse-shoe kidney
  • renal dysplasia

INVESTIGATIONS:

1. Karyotype

  • 49, XXXXX karyotype

MANAGEMENT:

1. Supportive

  • Paediatrics, Endocrinology, Neurology, Cardiology, Dental, Orthopedics
  • genetic counselling
  • supplemental teaching for poor school performance

ADDITIONAL REFERENCES:

1. Jones, K.L., Smith's Recognizable Patterns of Human Malformation (5th Edition), p. 80, (1997).
2. Baraitser, M. and R.M. Winter, Color Atlas of Congenital Malformation Syndromes (1st Edition), p. 13, (1996).

 

 

 

 

Pediatric Database - XXXXX SYNDROME

Pediatric Organization - Pedbase [at] Gmail.com