Type I hyperprolinemia in a family suffering from aniridia and severe dystrophia of ocular tissues

Hyper prolinuria and hyper-hydroxy prolinuria in children with mental retardation

Three thousand cases with mental retardation referred from different hospitals were screened for aminoacid disorders. Among them one case of hyperprolinuria and another case of hyperprolinuria with hyper hydroxyprolinuria were detected. These are the first cases to be reported from the state of Andhra Pradesh.

Type I hyperprolinemia

Type I hyperprolinemia is an autosomal recessive disorder characterized by increased plasma and urine proline concentrations due to a deficiency of the enzyme, proline oxidase. This rare inborn error of proline metabolism is generally believed to be a benign condition although many associated clinical abnormalities have been reported. We report two siblings with Type I hyperprolinemia who presented with recurrent seizures. They had elevated plasma proline levels with massive prolinuria without an increased urinary excretion of delta 1-pyrolline-carboxylic acid.

Delay in diagnosis of homocystinuria: retrospective study of consecutive patients

OBJECTIVE

To assess the causes for delay in the diagnosis of homocystinuria.

DESIGN

Clinical and laboratory data were collected from patients diagnosed as having homocystinuria due to cystathionine synthase deficiency, with special reference to the ages at which the patients had their first major signs of the disease, ectopia lentis was established, and homocystinuria was diagnosed.

SETTING

University hospital in the Netherlands.

SUBJECTS

34 patients (18 males) in whom homocystinuria due to cystathionine synthase deficiency was diagnosed in the period 1970-94.

RESULTS

Among 34 consecutively detected homocystinuria patients the mean age at diagnosis of homocystinuria was 24 (range 1-61) years. Despite frequent ocular manifestations, serious complications in the vascular, skeletal, and central nervous systems, and repeated examinations performed in these patients by clinicians of various disciplines, there was a mean delay of 11 (0-43) years between the first major signs of the disease (at mean age 13 (1-40) years) and the ultimate diagnosis of homocystinuria. Even when ectopia lentis was diagnosed (in 26 (76%) patients, mean age 18 (1-50) years), this did not lead to adequate biochemical analysis for homocystinuria at the time of detection, causing a mean diagnostic delay of 8 (0-24) years in these patients.

CONCLUSIONS

Three factors should have precipitated the diagnosis of homocystinuria: early recognition that unusual myopia (high, very high, abnormal progressive, or at young age) was caused by subluxation of the ocular lenses; awareness that the occurrence of myopia combined with systemic complications ("myopia plus") might be due to homocystinuria; and appropriate biochemical investigations carried out in patients with ectopia lentis and in their siblings.

Hyperprolinaemia type I and white matter disease: coincidence or causal relationship?

We describe a 10-year-old boy with hyperprolinaemia type I and severe neurological abnormalities (mental retardation, cerebral palsy, epilepsy, nystagmus). Magnetic resonance imaging showed diffuse white matter involvement and electroretinography confirmed tapetoretinal degeneration. In view of reports in the literature, hyperprolinaemia type I may not be a benign condition, as usually assumed, but may lead to marked neurological abnormalities, particularly in affected males.

Effect of proline administration on rat behavior in aversive and nonaversive tasks

Sustained levels of proline comparable to those of human type II hyperprolinemia were achieved in blood and brain of rats subcutaneous proline administration twice a day from the 6th till the 28th day of life. Control rats were treated with saline in the same volumes. Behavioral studies using aversive and nonaversive tasks were performed one week or one month after treatment. Proline treatment did not affect rats' performance in the inhibitory avoidance task, but reduced significantly habituation in the open field. Our results seem to indicate that early postnatal administration of proline to rats affects habituation to a novel environment. If this happens to be so the present tendency to consider hyperprolinemia as a benign condition should be revised.