Case notes

A routine anatomical survey performed at 21 weeks’ gestation in a 34 year old multiparous Asian woman revealed a female fetus with thickening of the dorsal aspect of both feet ( Figure 1 ). Although this isolated finding suggested the presence of Milroy disease, it was also considered suspicious for Turner syndrome. Genetic amniocentesis disclosed a final karyotype of 45,X in 20 cells, consistent with a diagnosis of Turner syndrome. The parents were counseled about the result and opted for termination of pregnancy.

An ultrasonographic view of the fetus demonstrates dorsal foot edema.

Hoskovec. A foot path to diagnosis. Am J Obstet Gynecol 2013.

In a second case, the routine anatomical survey performed at 22 weeks’ gestation in a 41 year old Hispanic woman showed a female fetus with thickening of the dorsal aspect of both feet ( Figure 2 ). No evidence of other abnormalities was seen. Amniocentesis was declined, and at 38 weeks’ gestation, the patient delivered a girl who was small for gestational age. Clinical stigmata of Turner syndrome were noted at delivery. A blood chromosome analysis reported a 45,X karyotype, confirming the diagnosis.

So-called puffy feet can serve as a prenatal marker for Turner syndrome.

Hoskovec. A foot path to diagnosis. Am J Obstet Gynecol 2013.

Conclusions

Turner syndrome is a common chromosomal abnormality. The cardinal signs on prenatal sonographic examination include nuchal cystic hygroma, general edema, brachycephaly, and cardiac defects. Provided such findings are recognized, invasive prenatal diagnosis can then be proposed. Lymphedema of the hands and feet (puffy feet) is one of the morphological characteristics of Turner syndrome in neonates and spontaneous abortion specimens. About 30% of patients have this trait, which is possibly related to a congenital lymphatic system defect. With that in mind, the diagnosis of Turner syndrome was considered in the cases presented here.

Milroy disease (hereditary lymphedema type I) is included in the differential diagnosis because it is characterized by lower-limb lymphedema. The condition has been diagnosed by prenatal ultrasonography upon detection of swelling of the dorsum of the feet. It is inherited in an autosomal dominant manner or is caused by a de novo mutation with resultant dysgenesis of microlymphatic vessels.

To the best of our knowledge, this is the first report of prenatal diagnosis of Turner syndrome based on the single ultrasonographic finding of dorsal foot edema in a female fetus. A MedLine search was conducted with no time or language limits, using the search terms, fetal foot edema, Turner syndrome, monosomy X, and prenatal ultrasound.

In all probability, isolated foot swelling in the fetus is the early expression of the congenital lymphedema known to occur in many patients with postnatally diagnosed Turner syndrome. Our cases suggest that dorsal foot edema on ultrasound is a potentially useful prenatal marker of Turner syndrome, justifying the offer of fetal chromosome analysis.