Case report

This patient was referred  to our unit for anomaly scan due to severe oligohydramnios at 16 weeks of pregnancy. The patient had no medical disorder nor consanguinity, or any other important clinical record.

Our ultrasound examination revealed the following findings:

-Anhydramnios
-Microphthalmia
-Deformed skull bones due to pressure effect
-Bilateral enlarged echogenic lungs
-Eversion of diaphragm
-Fluid-filled bronchi
-Compression of heart

These findings suggest the diagnosis of laryngeal atresia  or congenital high airway obstruction (CHAOS).

We also found ascites, absent bladder and flattened adrenal glands in transvaginal examination, compatible with the diagnosis of bilateral renal agenesis.

Based on the ultrasound findings, the preposed prenatal diagnosis was Fraser syndrome, and it was confirmed postnatally.

Congratulation to Javier Cortejoso for his perfect answer!!!

Images 1-5: 2D transabdominal and transvaginal ultrasound images of the fetus showing the anhydramnios, enlarged and echogenic lungs with eversion of diaphragms, compression of the heart and flattened adrenal glands.

Images 6: tomographic ultrasound image showing enlarged and echogenic lungs, eversion of diaphragm, compressed heart, consistent with laryngeal atresia.

Videos 1-5: 2D transabdominal and transvaginal ultrasound images of the fetus showing the anhydramnios, enlarged and echogenic lungs with eversion of diaphragms, compression of the heart and flattened adrenal glands.

Definition: Fraser syndrome is characterized by cryptophthalmos, cutaneous syndactyly of the hands and feet, and anomalies of the respiratory and urogenital tracts (ambiguous genitalia and renal agenesis).

Synonyms: also known as cryptophthalmo ssyndactyly syndrome.

Incidence: incidence is 0.04 per 10,000 liveborn infants and 1.1 per 10,000 stillbirths.

Genetics: the genetic cause is heterogeneous and includes mutations in FRAS1, FREM2, or GRIP1. Inheritance is autosomal recessive with marked intrafamilial variability.

Recurrence risk: recurrence risk is 25% if both parents are found to be mutation carriers.

Diagnosis: the diagnosis is based on the combination major and minor characteristics, where three major, or two major and two minor, or one major and three minor diagnostic criteria are present.

Major criteria include syndactyly, cryptophthalmos, urinary tract anomalies, ambiguous genitalia, laryngeal or tracheal anomalies, and positive family history.

The minor criteria include anorectal defects, dysplastic ears, abnormal skull ossification, umbilical anomalies, and nasal anomalies.

Other features include cleft lip palate; skeletal anomalies; cardiac malformations; and anal atresia.

Many of these anomalies can be seen prenatally, but the specific diagnosis may be  difficult to determine until after birth.

Differential diagnosis: other syndromes with syndactyly, renal agenesis, and laryngeal anomalies include cutis aplasia, Nager acrofacial dysostosis, and Pallister-Hall syndrome, but they are all distinct from  Fraser syndrome.

Prognosis: The syndrome is fatal if laryngeal atresia or bilateral renal agenesis is present. If cryptophthalmos is present, even surgical repair will yield very poor vision (i.e., 20/200 and 20/360) in the rare correctable cases.

References

1. Berg C, Geipel A, Germer U, et al: Prenatal detection of Fraser syndrome without cryptophthalmos: case report and review of the literature. Ultrasound Obstet Gynecol 18(1):76-80, 2001.

2. Lesniewicz R, Sulik M, Midro AT: [Microphthalmos and hypertelorism as diagnostic index in ultrasound diagnosis of Fraser syndrome]. Ginekol Pol 76(2):147-152, 2005.

3. Okumus N, Onal EE, Turkyilmaz C, et al: Resuscitation failure due to Fraser syndrome in a newborn undiagnosed in the prenatal period. Resuscitation 65(2):221-223, 2005.

4. Prasun P, Pradhan M, Goel H: Intrafamilial variability in Fraser syndrome. Prenat Diagn 27(8):778-782, 2007.

5. Schanze D, Kayserili H, Satkin BN, et al: Fraser syndrome due to mutations in GRIP1-clinical phenotype in two families and expansion of the mutation spectrum. Am J Med Genet A 164A(3):837-840, 2014.

6. van Haelst MM, Scambler PJ, Fraser Syndrome Collaboration Group, Hennekam RC: Fraser syndrome: a clinical study of 59 cases and evaluation of diagnostic criteria. Am J Med Genet A 143A(24):3194-3203, 2007.

7. Vogel MJ, van Zon P, Brueton L, et al: Mutations in GRIP1 cause Fraser syndrome. J Med Genet 49(5):303-306, 2012.