Pearl – Vanishing Twins – Disruptions – Median Incisor

Median Incisor Holoprosencephaly SMMCI

An old adage in Medicine and Sciences asserts that clever investigators should cherish exceptions (or rare coincidences).

Illustrated here are two concurrent rare events:

  • perhaps a Solitary Median Maxillary Central Incisor (SMMCI) syndrome;
  • a vanished twin noted during early pregnancy.

It is known that the vanishing twin process often damages the surviving twin – you may learn much about it by viewing the superb presentation by Dr. K.L. Jones, a pioneer in Dysmorphology (click here). Furthermore, it is also known that anomalies of the 7q chromosomal region may be associated with the SMMCI syndrome. Lastly, the holoprosencephaly malformation complex is associated with midline anomalies, in particular of the corpus callosum. Please, see the video recording illustrating the behavior of this child which may be indicative of cerebral anomalies.

The above is sufficient to demonstrate the importance of rare anomalies and rare associations.