Hemoglobin Knossos: a clinical, laboratory, and epidemiological study

Area of Science:

• Hematology
• Medical Genetics

Background:

• Hemoglobin (Hb) Knossos is a beta-chain variant (beta 27 Ser----Ala) not detectable by standard separation techniques.
• This variant is characterized by reduced synthesis and interacts with beta-thalassemia.

Purpose of the Study:

• To summarize the genetic, clinical, and biochemical characteristics of Hb Knossos.
• To investigate the clinical presentation of double heterozygotes and carriers.

Main Methods:

• Globin electrophoresis on urea-Triton X-acrylamide gels and isoelectric focusing (IEF) for detection.
• Analysis of five double heterozygous cases and 12 heterozygous carriers from three families.

Main Results:

• Double heterozygotes (Hb Knossos and beta-thalassemia) exhibit features of thalassemia intermedia.
• Hb Knossos carriers show slightly decreased oxygen affinity, potentially compensating for anemia in double heterozygotes.
• A survey of 610 individuals found no heterozygotes, indicating rarity in the studied population.

Conclusions:

• Hb Knossos is a clinically significant beta-chain variant that interacts with beta-thalassemia.
• The variant may be more prevalent in Mediterranean countries.
• Specific electrophoretic methods are crucial for identifying Hb Knossos.