Isotretinoin phenocopy

✍ Scribed by Lammer, Edward J. ;Hayes, Ailish M. ;Optiz, John M. ;Reynolds, James F.

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 64 KB
• Volume: 29
• Category: Article
• ISSN: 0148-7299
• DOI: 10.1002/ajmg.1320290329

✦ Synopsis

Letter to the Editor lsotretinoin Phenocopy

To the Editor:

Recently, Lungarotti et al. [1987] reported on an infant with multiple congenital anomalies as showing "striking phenotypic similarity" to the retinoic acid embryopathy. We have examined more than 28 infants with major malformations associated with maternal use of isotretinoin, as well as collected autopsy reports, medical records, and/or photographs of 20 additional cases. Based on our findings, this child bears very little similarity to the retinoic acid phenotype.

Intrauterine growth retardation is uncommon in the retinoic acid embryopathy. Growth retardation as significant as in the case of Lungarotti et al. [1987] has not occurred. The ear malformations are not typical of retinoic acid embryopathy. In that embryopathy, preauricular tags are rare, occur singly, and have only occurred just anterior to the tragus, not in a line toward the mouth. Unlike this child, infants with retinoic acid embryopathy who lack external auditory canals have almost no auricular tissue present. The severity of micrognathia in this case is also not typical of retinoic acid embryopathy. Microstomia, microglossia, glossoptosis, and redundant skin folds have not been seen. Atrial septa1 defect is not a typical cardiac defect. The common cardiac malformations are aorticopulmonary septation abnormalities and branchial arch mesenchymal tissue defects. None of the abdominal anomalies found in this case (duodenal atresia, biliary atresia, renal hypoplasia) have been found in the retinoic acid embryopathy to date. This case is not a phenocopy of the retinoic acid embryopathy. The mother's daily vitamin A supplementation (2,000 IU) is only 25% of the vitamin A currently supplied in standard prenatal vitamins in the U.S. It is improbable that the vitamin A supplement played a role in the genesis of this child's malformations.