ESPN 51th Annual Meeting

ESPN 2018


 
CARBONIC ANHYDRASE II DEFICIENCY IN THREE SIBLINGS
AYŞE DERYA BULUŞ 1 ASLI ÇELEBI TAYFUR 2 DENİZ YILMAZ 3

1- UNIVERSITY OF HEALTH SCIENCES, KEÇİÖREN TRAINING AND RESEARCH HOSPITAL, DEPARTMENT OF PEDIATRIC ENDOCRINOLOGY
2- UNIVERSITY OF HEALTH SCIENCES, KEÇİÖREN TRAINING AND RESEARCH HOSPITAL, DEPARTMENT OF PEDIATRIC NEPHROLOGY
3- UNIVERSITY OF HEALTH SCIENCES, KEÇİÖREN TRAINING AND RESEARCH HOSPITAL, DEPARTMENT OF PEDIATRIC NEUROLOGY
 
Introduction:

The carbonic anhydrase II (CA II) deficiency syndrome (Guibaud-Vainsel syndrome)  is a rare autosomal recessive disorder with cardinal features of osteopetrosis, renal tubular acidosis, and cerebral calcification. Other features include visual and auditory impairment, short stature, a large cranial vault, multiple skeletal fractures, growth retardation, developmental delay and cognitive defects. The renal tubular acidosis is usually a mixed type. The metabolic derangement may be partially treated with bicarbonate, bone marrow transplantation or possibly gene therapy.

Material and methods:

We describe three siblings of CAII  deficiency syndrome from healthy consanguineous Turkish parents.

Results:

Two sisters aged  13 and 16 years were referred to Pediatric Endocrinology Outpatient Clinic due to recurrent long bone fractures. On physical examination, the sisters were found to have  prominent forehead, flattened nasal bridge, dental malocclusion and dental caries, growth retardation and cognitive defects. Laboratory and imaging studies showed increased bone density, cerebral calcification, distal renal tubular acidosis in both patients and urolithiasis in one. Their 3 years old brother with developmental delay also showed cardinal features of CA II deficiency. They were started on sodium bicarbonate (2 mEq/kg/day) and potassium citrate (2 mEq/kg/day). The genetic study of the patiets revealed a homozygous deletion mutation from exon 3 to 7 in the CAII gene.

Conclusions:

 Carbonic anhydrase II deficiency syndrome should be thought in diffrential diagnosis of osteopetrosis manifesting without severe hematologic findings. Early treatment of systemic acidosis with bicarbonate may be crucial in the outcome of CAII deficiency syndrome.