connatal

The disease form in early infancy is referred to as connatal PMD and diagnosis in later childhood is most typically associated with the classic form.

Health News from Medical News Today 2009

Simply this -- that all necessity for supposing immediate impressions made upon our understandings by God, or other supernatural, or antenatal, or connatal, agencies, is idle and romantic; for that, upon examining the furniture of our minds, nothing will be found there which cannot adequately be explained out of our daily experience; and, until we find something that cannot be solved by this explanation, it is childish to go in quest of higher causes.

The Uncollected Writings of Thomas de Quincey—Vol. 1 With a Preface and Annotations by James Hogg Thomas De Quincey 1822

Those with the most severe form of the disease, connatal PMD, lose the ability to walk and talk and eventually die, often before the age of 10.

StemCells, Inc. Reports Progress in Myelination Disorder Trial - Yahoo! Finance 2010

The term congenital peculiarity, I may remark, is a loose expression and can only mean a peculiarity apparent when the part affected is nearly or fully developed: in the Second Part, I shall have to discuss at what period of the embryonic life connatal peculiarities probably first appear; and I shall then be able to show from some evidence, that at whatever period of life a new peculiarity first appears, it tends hereditarily to appear at a corresponding period {192}.

The Foundations of the Origin of Species Two Essays written in 1842 and 1844 Charles Darwin 1845