Login processing Curr Opin Genet Dev. This is a sample clip. The extra genetic material in these cases can lead to skeletal abnormalities, decreased IQ, and delayed development, but the features of these conditions are variable.
Fragile X syndrome is characterized by a wide range of developmental problems, including learning disabilities. Conditions resulting from mutations in mitochondrial DNA can appear in every generation of a family and can affect both males and females, but fathers do not pass these disorders to their daughters or sons.
Many genes in the pseudoautosomal regions are essential for normal development.
Male Pattern Baldness Hemophilia — a condition lacking the enzyme for blood clotting Duchenne Muscular Dystrophy — Muscular weakness, progressive deterioration of muscle tissue, and loss of coordination. It is a condition where individuals have 47 chromosomes in each cell instead of Extra or missing chromosomes Another type of sex-linked disorder has too many or too little chromosomes.
A new look at XXYY syndrome: medical and psychological features. In males who have only one X chromosome , a mutation in the only copy of the gene in each cell causes the disorder. Y Chromosome Fact Sheet. Rarely, males may have more than one extra copy of the Y chromosome in every cell polysomy Y.
Both alleles influence the genetic trait or determine the characteristics of the genetic condition.