title: Male infants with hypospadias and/or cryptorchidism show a lower 2D/4D digit ratio than normal boys.
abstract: BACKGROUND
  In humans the ratio of the index finger to the ring finger is sexually dimorphic, with the mean ratio being larger in women than in men. It has been suggested that this difference is related to prenatal androgen exposure. This has been further demonstrated in children with congenital adrenal hyperplasia. Normal development of the male external genitalia is linked to androgen-mediated events during gestation. We therefore wanted to determine if the 2D:4D digit ratio was normal in boys with cryptorchidism or hypospadias.
  
  
  METHODS
  We prospectively enrolled all prepubertal patients seen in the outpatient clinic for cryptorchidism or hypospadias between September and December 2012. We then compared their 2D:4D digit ratio with two control groups made up of normal boys and normal girls. Interobserver and intraobserver variability was evaluated.
  
  
  RESULTS
  We included 57 boys with hypospadias and/or cryptorchidism, 79 boys without genital abnormalities and 25 girls without genital abnormalities. The mean 2D:4D ratio for both hands was significantly different between the three groups, with the digit ratio for boys with genital anomalies being lower than for normal boys and normal girls (p<0.0001).
  
  
  CONCLUSIONS
  It appears that boys with genital abnormalities (cryptorchidism and/or hypospadias) have a lower 2D:4D digit ratio than boys without genital anomalies.
authors: Department of Pediatric Surgery, CHU F Guyon, Bellepierre, Saint-Denis de La Réunion, Reunion Island, France.
authors: O
authors: O
authors: Abbo
authors: Unité de Soutien Méthodologique, CHU F Guyon, Bellepierre, Saint-Denis de La Réunion, Reunion Island, France.
authors: C
authors: C
authors: Ferdynus
authors: Department of Pediatric Surgery, Hôpital Lapeyronie, CHU Montpellier, Montpellier, France.
authors: N
authors: N
authors: Kalfa
authors: Unité de Soutien Méthodologique, CHU F Guyon, Bellepierre, Saint-Denis de La Réunion, Reunion Island, France.
authors: L
authors: L
authors: Huiart
authors: Department of Pediatric Surgery, CHU F Guyon, Bellepierre, Saint-Denis de La Réunion, Reunion Island, France.
authors: F
authors: F
authors: Sauvat
authors: Department of Pediatric Surgery, CHU F Guyon, Bellepierre, Saint-Denis de La Réunion, Reunion Island, France.
authors: L H
authors: LH
authors: Harper
mesh_terms: D000886:Anthropometry / Q000379:methods; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003456:Cryptorchidism / Q000196:embryology / Q000473:pathology*; D005260:Female; D005385:Fingers / Q000196:embryology / Q000473:pathology*; D006801:Humans; D007021:Hypospadias / Q000196:embryology / Q000473:pathology*; D007223:Infant; D008297:Male; D015588:Observer Variation; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011446:Prospective Studies; D015203:Reproducibility of Results; D012727:Sex Characteristics
keywords: Endocrinology; General Paediatrics; Neonatology; Paediatric Surgery