Prenatal diagnosis of Lesch-Nyhan syndrome by purine analysis of amniotic fluid and cordocentesis

The analysis of human amniotic fluid using capillary electrophoresis

This study has investigated the composition of amniotic fluid (AF) using capillary electrophoresis (CE). A detailed optimisation investigation was undertaken to obtain the best resolution of the major peaks in amniotic fluid. In the final method, capillary zone electrophoresis (CZE) of AF was performed on a Hewlett Packard3D CE instrument using a fused-silica capillary of 44 cm total length (36 cm to the detector) with in internal diameter of 50 microm. The background electrolyte was 20 mM sodium tetraborate containing 0.8 mM EDTA adjusted to pH 9.0. AF was diluted 1 plus 1 with deionised water prior to hydrodynamic injection for 3 s at 50 mbar. The separation was performed at +22.5 kV and resulted in a current of 65 microA. The capillary temperature was 28 degrees C. Using this CZE method, some eight peaks were consistently resolved in AF samples and several other more transient peaks have been separated from AF in less than 10 min. A scheme for the identification of peaks once they had been separated was also developed. Four peaks have been identified as proteins, i.e., gamma-globulin, alpha1-antitrypsin, transferrin and albumin. Surprisingly, one major peak was shown to be the purine catabolite, xanthine.

Atlantoaxial instability in Lesch-Nyhan syndrome

STUDY DESIGN

A clinical case report of two brothers with Lesch-Nyhan syndrome found to have atlantoaxial instability is reported.

OBJECTIVES

To report the clinical and radiologic findings and the operative outcome in these patients.

SUMMARY OF BACKGROUND DATA

Both patients had biochemically proven Lesch-Nyhan syndrome. No previous cases of cervical instability have been reported in this group of patients.

METHODS

The first patient presented with neck pain and progressive quadriplegia. Radiology including computed tomography scanning showed fracture of the tip of the odontoid and forward subluxation of the atlas. He was treated with a C1-C2 Gallie fusion. The second patient (his brother) was found to have similar radiologic findings but had not developed quadriplegia. He has not required surgery.

RESULTS

At surgery, attempted correction of the subluxation produced severe bradycardia. An in situ fusion was performed that relieved the patient's neck pain. The child's neurologic status has remained the same during a 16-month follow-up period, despite failure of the posterior wire fixation 12 months after surgery.

CONCLUSIONS

Patients with Lesch-Nyhan syndrome may develop atlantoaxial instability with subsequent neck pain and quadriplegia that may be masked by their underlying disease. Posterior fusion produced symptomatic relief but no improvement in neurologic status in our patient. Posterior fusion probably should be augmented by rigid cervical immobilization until fusion is confirmed in this type of patient.