HIBCH Deficiency: A Comprehensive Review Introduction 3-Hydroxyisobutyryl-CoA hydrolase (HIBCH) deficiency (OMIM #250620) is an extremely rare autosomal recessive inborn error of valine catabolism that leads to severe neurological manifestations and mitochondrial dysfunction. First described in 1982, this devastating condition has been reported in fewer than 100 patients worldwide, with most cases presenting in early infancy …
HGSNAT Deficiency: A Comprehensive Medical Review Introduction HGSNAT deficiency, also known as mucopolysaccharidosis type IIIC (MPS IIIC) or Sanfilippo syndrome type C, is a rare autosomal recessive lysosomal storage disorder caused by deficiency of the enzyme heparan-α-glucosaminide N-acetyltransferase (HGSNAT). According to trusted medical organizations including the National Institutes of Health (NIH), Orphanet, and the National …
HEM Dysplasia: A Comprehensive Medical Review Introduction HEM dysplasia, also known as Greenberg dysplasia or Hydrops-Ectopic calcification-Moth-eaten skeletal dysplasia, is an extremely rare autosomal recessive skeletal disorder first described by Greenberg and colleagues in 1988. According to trusted medical organizations including Orphanet, the National Organization for Rare Disorders (NORD), and the National Institutes of Health …
HEC Syndrome: A Comprehensive Medical Review Introduction HEC syndrome, standing for Hydrocephalus, Endocardial fibroelastosis, and Cataracts, is an extremely rare genetic disorder first described by Devi and colleagues in 1995. According to trusted medical organizations including Orphanet, the National Organization for Rare Disorders (NORD), and the National Institutes of Health (NIH), this syndrome is characterized …
HDR Syndrome: A Comprehensive Medical Review Introduction HDR syndrome, also known as Barakat syndrome or hypoparathyroidism-sensorineural deafness-renal disease syndrome, is an extremely rare autosomal dominant genetic disorder first described by Ali J. Barakat and colleagues in 1977. According to trusted medical organizations including Orphanet, the National Organization for Rare Disorders (NORD), and the National Institutes …
HARD Syndrome: A Comprehensive Medical Review Introduction HARD syndrome, which stands for Hydrocephalus, Agyria, Retinal Dysplasia (with or without Encephalocele, making it HARD±E syndrome), is the original terminology for what is now more commonly known as Walker-Warburg syndrome (WWS). According to trusted medical organizations including the National Institutes of Health (NIH), Orphanet, and the National …
HANAC Syndrome: A Comprehensive Medical Review Introduction Hereditary angiopathy with nephropathy, aneurysms, and muscle cramps (HANAC) syndrome is an extremely rare autosomal dominant multisystem disorder first comprehensively characterized by Plaisier and colleagues in 2007. According to trusted medical organizations including the National Institutes of Health (NIH), Orphanet, and the National Organization for Rare Disorders (NORD), …