Contiguous ABCD1 DXS1357E deletion syndrome: Report of an autopsy case

Only nine individuals with CADDS have been reported in the medical literature to date.

“Only nine individuals with this diagnosis have been reported in the medical literature to date.”

Since the first description, a further six patients with a similar phenotype and variable deletions involving ABCD1 and BCAP31 have been reported, including one symptomatic girl.

“Since then, a further six patients with a similar phenotype and variable deletions involving these contiguous genes have been reported, including one symptomatic girl. 6 , 7 , 8 , 9”

Raised VLCFA in CADDS is like that seen in isolated ABCD1 defects.

“As in DDCH, severe developmental delay, dystonia, deafness, and white matter abnormalities are commonly reported, while the presence of raised VLCFA is like that seen in isolated ABCD1 defects.”

In CADDS, severe developmental delay, dystonia, deafness, and white matter abnormalities are commonly reported.

“As in DDCH, severe developmental delay, dystonia, deafness, and white matter abnormalities are commonly reported, while the presence of raised VLCFA is like that seen in isolated ABCD1 defects.”

Unlike DDCH or X-ALD, CADDS affected males have persistent cholestatic liver disease.

“However, unlike either DDCH or X‐ALD, CADDS affected males have persistent cholestatic liver disease and commonly die in infancy. 5 , 6 , 7 , 8 , 9”

CADDS affected males commonly die in infancy.

“However, unlike either DDCH or X‐ALD, CADDS affected males have persistent cholestatic liver disease and commonly die in infancy. 5 , 6 , 7 , 8 , 9”

The impact of SRPK3 deletion in the patient and two others is unclear due to early mortality reported in CADDS.

“The impact of its deletion in our patient and two others is unclear, however, due to the early mortality reported in CADDS.”

Death from respiratory causes is reported in 50% of males with CADDS.

“overall, death from respiratory causes is reported in 50% of males with CADDS. 5 , 6”

Congenital heart disease did not feature in any of the CADDS patients with PLXNB3 involvement.

“congenital heart disease did not feature in any of the CADDS patients with PLXNB3 involvement.”

Previous studies have reported normal plasmalogen levels in blood and cultured fibroblasts, with normal peroxisomal size, number and assembly demonstrated in liver tissue by electron microscopy and immunochemistry.

“Previous studies, have reported normal plasmalogen levels in blood and cultured fibroblasts, with normal peroxisomal size, number and assembly demonstrated in liver tissue by electron microscopy and immunochemistry. 5 , 6”

Most CADDS individuals presented in early infancy with hepatic cholestasis, severe growth failure, profound hypotonia, developmental delay and elevated VLCFAs.

“most individuals presented in early infancy with hepatic cholestasis, severe growth failure, profound hypotonia, developmental delay and elevated VLCFAs (Table 2).”

BCAP31 deficiency potentially exacerbates the peroxisomal phenotype in CADDS, although the mechanisms remain unclear.

“BCAP31 deficiency potentially exacerbates the peroxisomal phenotype in CADDS, although the mechanisms remain unclear. 6”