What are the characteristics of the following genetic disorders: mosaic germ line, DiGeorge syndrome, cri-du-chat syndrome, and Huntington's diseas...

What are the characteristics of the following genetic disorders: mosaic germ line, DiGeorge syndrome, cri-du-chat syndrome, and Huntington's disease?
Mosaic germ line
DiGeorge syndrome
Cri-du-chat syndrome
Huntington's disease
When genetic tests are performed using blood or tissue samples from these individuals, the result will be negative for the mutation.,Germline mosaicism can be seen with a relatively genetic pattern, however, it is most commonly observed in X-linked and autosomal dominant disorders.,Ex: Turner syndrome
A particularly common microdeletion involves chromosome 22q11.2 and is associated with the diagnosis of DiGeorge syndrome.,Deletion on the long arm of chromosome 22 in the 11.2 region of the TBX1 gene.,Autosomal dominant inheritance. It is a rare syndrome.,Patients have typical craniofacial anomalies, intellectual deficiency, immunodeficiency, and cardiac defects, probably reflecting haploinsufficiency for one or more of the several dozen genes that are normally found in this region.,Expressions: heart problems, lack of calcium, immune system deficiency, developmental delay, among others.
Formed by a terminal or interstitial deletion of part of the short arm of chromosome 5.,Chromosome 5 - short arm - deletion of the 5p segment.,Autosomal inheritance.,This deletion syndrome received its common name because the cry of infants with this disorder sounded like a cat's meow.,The breakpoints and extent of the deleted segment of chromosome 5p are highly variable among different patients, but the critical region absent in all patients with the phenotype has been identified as being band 5p15.,Expressions: low birth weight, hypotonia, microcephaly, rounded face, hypertelorism, strabismus, and nose with widened base.
Results from a dynamic mutation.,It is an autosomal dominant disease.,Mutation by insertion, being a neurodegenerative disease.,Expansion of CAG trinucleotide repeats in exon 1 of the HTT gene.,The protein formed is huntingtin that causes the death of neurons in various parts of the brain.,The disease is transmitted from generation to generation with a 50% risk for each descendant, and heterozygous and homozygous patients for the mutation have a very similar phenotype, although homozygotes may have a faster course of the disease.,There are, however, obvious peculiarities in its inheritance that cannot be explained by the simple rules of Mendelian genetics.