Heimler Syndrome: A Comprehensive Medical Review Introduction Heimler syndrome (also known as deafness-enamel hypoplasia-nail defects syndrome; OMIM #234580, #616617) is an ultra-rare autosomal recessive disorder characterized by the classic triad of sensorineural hearing loss, amelogenesis imperfecta (enamel hypoplasia) affecting primarily the secondary dentition, and nail abnormalities, with occasional or late-onset retinal pigmentation abnormalities. First described …
Hecht Syndrome (Trismus-Pseudocamptodactyly Syndrome): A Comprehensive Medical Review Introduction Hecht syndrome, also known as trismus-pseudocamptodactyly syndrome (TPS) or Distal Arthrogryposis Type 7 (DA7), is a rare autosomal dominant disorder of muscle development characterized by congenital contractures of the temporomandibular joint resulting in an inability to fully open the mouth (trismus) and short muscle and tendon …
Hemoglobin SC (HbSC) Disease: A Comprehensive Medical Review Introduction Hemoglobin SC disease (HbSC) is a genetic hemoglobinopathy resulting from the compound heterozygous inheritance of hemoglobin S (HbS; β6Glu→Val) and hemoglobin C (HbC; β6Glu→Lys), representing the second most common form of sickle cell disease after homozygous HbSS disease, accounting for approximately 20-30% of all sickle cell …
Hemoglobin SD (HbSD) Disease: A Comprehensive Medical Review Introduction Hemoglobin SD disease (also known as HbSD Punjab, sickle cell-hemoglobin D compound heterozygosity, or HbS/D Punjab disease) is a rare genetic hemoglobinopathy characterized by the compound heterozygous inheritance of hemoglobin S (HbS) and hemoglobin D Punjab (HbD), resulting in a variant form of sickle cell disease …
Hemoglobin SE (HbSE) Disease: A Comprehensive Medical Review Introduction Hemoglobin SE disease (also known as HbSE compound heterozygosity or sickle cell-hemoglobin E disease) is a rare genetic hemoglobinopathy characterized by the compound heterozygous inheritance of hemoglobin S (HbS) from one parent and hemoglobin E (HbE) from the other, resulting in a unique variant of sickle …
Hemoglobin H (HbH) Disease: A Comprehensive Medical Review Introduction Hemoglobin H disease (also known as HbH disease or alpha-thalassemia intermedia) is a moderate to severe form of alpha-thalassemia characterized by the deletion or inactivation of three out of four alpha-globin genes, resulting in moderately severe hemolytic anemia, splenomegaly, and variable clinical severity. Named for the …
Hay Wells Syndrome: A Comprehensive Medical Review Introduction Hay-Wells syndrome (also known as AEC syndrome or ankyloblepharon-ectodermal dysplasia-clefting syndrome; OMIM #106260) is a rare autosomal dominant ectodermal dysplasia characterized by the distinctive triad of ankyloblepharon (fusion of eyelid margins), severe ectodermal dysplasia with prominent skin erosions, and cleft lip and/or palate. First described by Hay …