LA RONGE SYNDROME

• Autosomal recessive disorder. Karyotype usually normal.
• Found exclusively in the Cree Indian population of La Ronge (small town in northern Saskatchewan, Canada). Arises due to the presence of consanguity in this population.

ULTRASOUND

• Head and Face
• Microcephaly, variable craniosynostosis, small eyes, broad nose, micrognathia, microstomia, normal ears.
• Upper Limbs (severely abnormal)
• Short forearms, fixed elbows, and abnormal hands (two well developed central digits with a less well developed index finger). Variable pattern of development of the thumb and little finger (absent or bifid). Forearm bones may be present, shortened or absent. An absent radius appears to be more common than an absent ulna. There may be humeroulnar fusion.
• Lower Limbs (less severe)
• Normal / shortened leg / absent fibulae.
• Less common skeletal anomalies include vertebral anomalies, dislocated hips.
• Severe IUGR.

PROGNOSIS

Death in utero or soon after birth.