Familial infantile olivopontocerebellar atrophy

CDG type Ia and congenital cytomegalovirus infection: two coexisting conditions

Congenital disorders of glycosylation are a heterogeneous group of disorders with multisystemic involvement. The most common form is phosphomannomutase deficiency or congenital disorders of glycosylation type Ia with an autosomal recessive inheritance and incidence estimated at 1/20000-1/50000 live born. Congenital disorders of glycosylation Ia can manifest as severe multisystemic disease of infancy or milder disorder with only neurological problems including ataxia, hypotonia, and psychomotor retardation. The brain pathological findings in congenital disorders of glycosylation type Ia patients corroborate with cerebellar dysfunction. Usually the most affected part is the anterior lobe of the vermis. Microscopic analysis demonstrates the prominent Purkinje cell loss and subtotal loss of the external and internal granule cell layers. The authors present clinical and pathological picture of a 4-month-old girl with congenital disorders of glycosylation type Ia, additionally complicated by congenital cytomegalovirus infection. The diagnosis was confirmed by low phosphomannomutase activity in patient's fibroblasts and mutations on both alleles of phosphomannomutase 2 gene.

Juvenile global tremor: a clinicopathologic syndrome mimicking polymyoclonia

Olivary nucleus degeneration is one of the pathologic characteristics of infantile olivopontocerebellar atrophy. It has also been described in premature neonates and infants with severe perinatal asphyxia and is thought to represent retrograde transsynaptic changes from cerebellar hemisphere lesions. A 2-year-old boy developed global tremor after a respiratory infection with remission after corticosteroid therapy, and recurrence of the tremor during gradual withdrawal of steroids. Neuropathologic examination revealed neuronal loss and gliosis in the lateral portions of both inferior olivary nuclei without associated abnormalities in the cerebellum. This appears to be a unique case, both clinically and neuropathologically.

Pontocerebellar hypoplasia type 2 and Reye-like syndrome

Pontocerebellar hypoplasia is an autosomal recessive syndrome with onset during the fetal period. Two subtypes of pontocerebellar hypoplasia have been described on the basis of clinical and neuropathologic criteria. Pontocerebellar hypoplasia type 2 is characterized by progressive microcephaly, early onset of extrapyramidal dyskinesia, and near absence of motor and cognitive development, without signs of either spinal or peripheral involvement. We report a clinical observation of a patient with pontocerebellar hypoplasia type 2, a 3-year-old girl with progressive microcephaly, dystonic limb movements, and absence of motor and cognitive development. Cranial magnetic resonance imaging revealed pontocerebellar hypoplasia. At the age of 2 years, she suffered a Reye-like syndrome that worsened her condition. Differential diagnosis was established with intrauterine injuries, other malformative syndromes, and neurodegenerative or neurometabolic disorders, which can be associated with cerebellar hypoplasia.

Fatal outcome in a case of pontocerebellar hypoplasia type 2

Pontocerebellar hypoplasia (PCH) is a very rare congenital (autosomal recessive) condition with fetal onset. Only a few cases have been published on the basis of both clinical data (symptoms/neuroradiological imaging) and autopsy results. This paper reports on such a case involving a 1.5-year-old male infant. The child suffered from severe psychomotor delay, extrapyramidal dyskinesia and epileptic seizures, but did not exhibit signs of spinal muscular atrophy as related to PCH type 1. Magnetic resonance imaging (MRI) at the age of 6 months demonstrated olivo-pontine and bilateral cerebellar hypoplasia. The boy was unexpectedly found dead. Autopsy disclosed a severe aspiration of gastric contents as the final cause of death. The neuropathological examination confirmed PCH type 2 (according to Barth [Brain Dev., 15 (1993) 411-422]) with marked microcephaly and olivopontocerebellar hypoplasia. Histologically, decreased density of olivo-pontine neurons, reduction of granular and Purkinje's cell layers of the cerebellum, slight astroglial proliferation and fragmented appearance of the dentate nuclei were observed. The immunohistochemical expression pattern was determined using antibodies against glial fibrillary acidic protein, synaptophysin and neurofilament protein. Summarizing, typical features of PCH type 2 were present and proved by clinical course, MRI and autopsy. Despite severe symptoms due to a natural disease this rare neurogenetic entity can become of forensic interest, when sudden unexpected death occurs.

Prenatal diagnosis of fatal infantile olivopontocerebellar hypoplasia syndrome

We report the first case of prenatal diagnosis of fatal infantile olivopontocerebellar hypoplasia syndrome, OMIM 225753. Ultrasound findings noted at 28 weeks' gestation included polyhydramnios, a small stomach bubble, a small but morphologically normal cerebellum, dilatation of the fourth ventricle, and long periods of normal fetal movement punctuated by sudden bursts of violent seizure-like activity of the fetal extremities. At birth, the child was noted to be hypertonic, myoclonic, hyper-reflexic, demonstrated poor gastrointestinal motility, and had severe apneic episodes. Magnetic resonance imaging (MRI) demonstrated marked hypoplasia or atrophy of the cerebellum, pons and medulla, mild atrophy of the cerebral cortex, and mild ex vacuo venticulomegaly of the fourth, third and lateral ventricles. This child died from respiratory insufficiency at 14 days of age. The parents of this child had previously lost a child with similar clinical and anatomical findings. Prenatal sonographers should be aware of the existence of this rare syndrome and should look carefully at the size of the cerebellum in cases of polyhydramnios or when in utero 'seizure-like' activity is seen. The importance of establishing this diagnosis lies in the fact that it appears to have a very poor postnatal prognosis and is likely to be inherited as an autosomal recessive disease.

Congenital nephrotic syndrome: a novel phenotype of type I carbohydrate-deficient glycoprotein syndrome

Type I carbohydrate-deficient glycoprotein (CDG) syndrome is a genetic multisystem disorder generally without overt renal problems. We report a neonate with neurological abnormalities and congenital nephrotic syndrome of diffuse mesangial sclerosis type. Serum transferrin isoelectric focusing showed the typical abnormalities of type I CDG syndrome. Normal transferrin focusing findings in other patients with similar renal problems excluded the possibility of a secondary biochemical phenomenon. The diagnosis of type I CDG syndrome was confirmed by demonstration of a deficiency of phosphomannomutase. No evidence of pontocerebellar atrophy was found in imaging or at autopsy. We conclude that congenital nephrotic syndrome may occur in type I CDG syndrome, and that this diagnosis should be considered in patients with congenital nephrotic syndrome. Absence of pontocerebellar atrophy does not exclude the diagnosis of type I CDG syndrome.