Læknablaðið - 15.08.1991, Side 41

LÆKNABLAÐIÐ 1991; 77: 247-8.
247
NÝR DOKTOR í LÆKNISFRÆÐI -
MÁR H. TULINIUS
Hinn 19. apríl síðastliðinn lauk Már H.
Tulinius doktorsprófi frá Gautaborgarháskóla
Ritgerðin nefnist á frummáli: »Mitochondrial
encephalomyopathies in childhood«.
During a four-year period (1984-1988),
50 children with manifestations of central
nervous system and/or neuromuscular
disease combined with hyperlactatemia
were subjected to investigations which
aimed to identify and characterise children
with mitochondrial disorders. Besides
neurological, neurophysiological, cardiological
and ophthalmological evaluation, special
biochemical and morphological investigations
of quadriceps muscle biopsies were done,
including oximetric and spectrophotometric
analysis of the respiratory chain function,
enzyme histochemistry, electron microscopy
and analysis of mitochondrial DNA.
A diagnosis of mitochondrial disease was
based on the presence of at least two of
the following five criteria: 1) abnormal
oximetry, 2) abnormal spectrophotometry,
3) enzyme-histochemical evidence of
cytochrome-c oxidase deficiency, 4) deletions
or point mujations of mitochondrial DNA
and 5) abundant ultrastructurally abnormal
mitochondria. With these criteria, 20 patients
had mitochondrial disorders. In additional 10
cases a mitochondrial disorder was neither
excluded nor verified.
The 20 patients with verified mitochondrial
disorders were separated into one series
with mainly encephalopathy (n=14) and
another with mainly myopathy (n=6). The
encephalopathic patients had the following
syndromes: Keams-Sayre (n=2), MERRF
(myoclonus epilepsy and ragged red fibres)
(n=2), MELAS (mitochondrial myopathy,
encephalopathy, lactic acidosis and stroke-like
episodes) (n=3), Alpers (n=3), Leigh (n=l),
and other variants (n=3). In the myopathic
series, three patients had hypertrophic non-
obstructive cardiomyopathy.
Ultrastructural abnormalities of mitochondria
were the most common morphological
changes in the muscle biopsies. Complex-I
deficiency was most common among cases
with encephalopathy. All the myopathic cases
had complex-IV deficiency. Point mutations or
large deletions of the mitochondrial genome
with heteroplasmy were identified in six
encephalopathic patients.
Multi-organ involvement was common.
Organs which were frequently affected
included the heart (12/20), the eyes (12/20)
and the peripheral nerves (9/20). A family
history of similar disease was obtained in six
of 20 families.
EEG development was analysed in the
encephalopathic series (n=14) and in
additional 11 patients with mitochondrial
encephalomyopathies, investigated
between 1988 and 1990. Mitochondrial
encephalomyopathies were usually
accompanied by abnormal EEGs, which were