Table 1.

Descriptions of specific terminology

Terminology	Description
Mendelian disorder or disease	A genetic disorder that is caused by a change in a single genetic region (a variant in a gene or chromosome) and typically follows one of the patterns of inheritance defined by Gregor Mendel such as autosomal dominant, autosomal recessive, or X-linked.
Molecular genetic diagnosis or molecular diagnosis	The genetic variant thought to be responsible for a specific phenotype  Example: The molecular diagnosis for an infant with Noonan syndrome is the pathogenic variant in PTPN11 or another Noonan-spectrum gene
Stillbirth	Death after 20 weeks’ gestation prior to delivery, resulting in non-liveborn birth.
Neonatal death	Death from birth to 28 days post-natal age
Infant death	Death from birth to one year of age
Perinatal death	Death from 20 weeks’ gestation through the early neonatal period
Sudden, unexpected early neonatal death (SUEND)	Seemingly healthy neonate with a postnatal collapse within the first week of age
Sudden, unexpected infant death (SUID)	Seemingly healthy infant with a postnatal collapse between 1 week and 1 year of age
Sudden infant death syndrome (SIDS)	An unexpected and unexplained death of an infant under 1 year of age