By surveying >100 cross sections in each patient sample we performed
quantitative electron microscopy to determine the percentage of arm defects in
cilia from individuals homozygous for the hypomorphic p.His154Pro CCDC103
mutation. Red diamonds and triangles indicate results from 16
CCDC103 p.His154Pro homozygote PCD patients, where
triangles indicates the result of 4 repeat nasal brushings performed on patients
marked by a diamond. The comparator group of 16 individuals with PCD, indicated
by other symbols as shown, consists of 3 cases with DNAAF1
mutations (open diamonds), 2 DNAAF3 (black squares), 2
DNAH5 (dark blue diamonds), 3 LRRC6 (2 as
light blue diamonds, 1 contained within the filled purple circle), 2
ZMYND10 (contained within the filled purple circle) and 4
cases in whom no mutations in known genes could be identified (grey squares). 6
CCDC103 p.His154Pro samples (27%) of p.His154Pro samples showed complete
lack of both outer and inner dynein arms comparable to other gene mutations in
the graph (purple circle). The grey shaded area represents normal range counts
from >200 non PCD respiratory controls.30 Four CCDC103
p.His154Pro patients had counts within this normal range (one is a repeat sample
(triangle) which showed similar data). Individuals with CCDC103 p.His154Pro
mutation have a trend towards a distinctive pattern of partial loss of dynein
arms that diverges from total dynein arm loss in the comparator group.