Mitochondrial Complex I Deficiency, Nuclear Type 23

A number sign (#) is used with this entry because of evidence that mitochondrial complex I deficiency nuclear type 23 (MC1DN23) is caused by homozygous mutation in the NDUFA12 gene (614530) on chromosome 12q22. One such patient has been reported.

For a discussion of genetic heterogeneity of mitochondrial complex I deficiency, see 252010.

Clinical Features

Ostergaard et al. (2011) reported a 10-year-old girl, born of consanguineous Pakistani parents, with mitochondrial complex I deficiency manifesting as Leigh syndrome (see 256000). The patient had delayed motor development, with walking at age 20 months. From age 2 years, she showed progressive loss of motor abilities and developed scoliosis and dystonia. At age 10 years, she had poor growth, used a wheelchair, and had severe muscular atrophy and hypotonia. Hypertrichosis was noted. Vision and hearing were normal, and she attended a special school where she had learned to read and write.

Molecular Genetics

In a 10-year-old girl, born of consanguineous Pakistani parents, with complex I deficiency manifesting as Leigh syndrome, Ostergaard et al. (2011) identified a homozygous nonsense mutation in the NDUFA12 gene (614530.0001). The mutation was identified by homozygosity mapping followed by candidate gene sequencing.