autosomal recessive defect

NOUN
26 LETTERS · STARTS WITH A

autosomal recessive defect is a valid 26-letter word worth 37 points in Scrabble and 43 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
A1U1T1O1S1O1M3A1L1R1E1C3E1S1S1I1V4E1D2E1F4E1C3T1
1 + 1 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 0 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 4 + 1 + 0 + 2 + 1 + 4 + 1 + 3 + 1 =37 PTS
DOUBLE WORD → 74TRIPLE WORD → 111
MEANING

What does autosomal recessive defect mean?