Abstract
Fraser syndrome is an autosomal recessive multiple malformation syndrome. It has a
recurrence risk of 25% among siblings; therefore, prenatal diagnosis is important
for counseling of affected families. We describe three prenatal cases of Fraser syndrome.
Based on new diagnostic criteria, three major, two major, and two minor criteria or
one major and three minor criteria are needed for diagnosis of Fraser syndrome. It
includes six “major” manifestations, including syndactyly, cryptophthalmos spectrum,
ambiguous genitalia, urinary tract abnormalities, laryngeal and tracheal anomalies,
and positive family history with five “minor” defects, including anorectal defects,
dysplastic ears, skull ossification defects, umbilical defects, and nasal anomalies.
In all three of our cases, congenital high airway obstruction syndrome (CHAOS) was
a constant finding. Renal system anomalies, including renal agenesis and dysplastic
kidneys, anhydramnios, and ascites, were also found in all three cases. Prenatal diagnosis
of Fraser syndrome was confirmed genetically postnatally in two out of the three patients,
with an excellent correlation of antenatal sonographic findings with postnatal features
of the abortus. Certain anomalies like syndactyly and cryptophthalmos, which were
not possible to detect antenatally because of anhydramnios, were confirmed postnatally.
We conclude that cases with antenatal diagnosis of CHAOS and bilateral renal agenesis/dysplastic
kidneys must be advised for meticulous postnatal examination for the remaining features
of Fraser syndrome, especially ambiguous genitalia, cryptophthalmos, and syndactyly
and then confirm genetically to ensure appropriate counseling of the couple for future
pregnancy.
Keywords
ambiguous genitalia - bilateral renal agenesis - CHAOS - Fraser syndrome - syndactyly
- upper airway malformations - cryptophthalmos spectrum
