Hi bros,
Want to share this genetic "structure" that we may all have. I did a chromosome culture analysis on my baby and discovered that he has unusual karyotype at 22nd pair of Chromosome. As per gynae recommendation, both Kenneth & myself went for further test. They drew our blood and perform a chromosome culture analysis too. If one of us has the same "unusual karyotype" as baby, then it is ok. If not, it may indicate that baby may not be 100% healthy.
Thank god, the results came out yesterday and it was my chromosome. I have the same karyotype as baby, baby is fine! Yippee!
When I spoke to mum, I realised that she did Amniocentersis when she was pregnant with Shouxing. As she was 38 years old in her third pregnancy, Amniocentersis is a compulsory test for her. Her Amniocentersis results showed that Shouxing has something unusual at 22nd pair chromosome too. Mum could not remember exactly but just know the number "22"! She said blood was drawn from herself and dad. It was dad's karyotype that is unusual! I am pretty sure Shouxing & I are the same. But not sure of Shousheng.
There is nothing to be worried about, just thought to let you both know about it. So that when your future wife is pregnant, you will not be overly anxious over the initial test results. It was a very stressful for us these past two weeks. But relieved when I received the good news yesterday.
Thank god for a healthy baby! And yes, it is a baby Boy! Chromosome test showed "XY" so confirmed, it is a boy!
Cheers,
Sis
Correction: She's 36 when pregnant with me. =]
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May god bless our family to have another healthy and active baby boy!
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Anyway, I did a Wiki search on it to see what kind of chromosomal conditions it may bring about:
The following conditions are caused by changes in the structure or number of copies of chromosome 22:
22q11.2 deletion syndrome: Most people with 22q11.2 deletion syndrome are missing about 3 million base pairs on one copy of chromosome 22 in each cell. The deletion occurs near the middle of the chromosome at a location designated as q11.2. This region contains about 30 genes, but many of these genes have not been well characterized. A small percentage of affected individuals have shorter deletions in the same region.
The loss of one particular gene, TBX1, is thought to be responsible for many of the characteristic features of 22q11.2 deletion syndrome, such as heart defects, an opening in the roof of the mouth (a cleft palate), distinctive facial features, and low calcium levels. A loss of this gene does not appear to cause learning disabilities, however. Other genes in the deleted region are also likely to contribute to the signs and symptoms of 22q11.2 deletion syndrome.
22q13 deletion syndrome (Phelan-McDermid syndrome): The deletion of the distal tip of the chromosome 22 is related to moderate to severe developmental delay and mental retardation. This region includes the Shank3 gene, thought to be responsible for the neurological deficits of the syndrome (Wilson et al., 2003).
Almost all children affected by the 22q13 deletion have absent or severely delayed speech; minor facial dysmorphism; thin, flaky toenails; large, fleshy hands; large feet; prominent, poorly formed ears and other characteristics which are not visually apparent: hypotonia (97%); normal to accelerated growth (95%); increased tolerance to pain (86%); seizures (unknown percentage) [1].
Other chromosomal conditions: Other changes in the number or structure of chromosome 22 can have a variety of effects, including mental retardation, delayed development, physical abnormalities, and other medical problems. These changes include an extra piece of chromosome 22 in each cell (partial trisomy), a missing segment of the chromosome in each cell (partial monosomy), and a circular structure called ring chromosome 22 that is caused by the breakage and reattachment of both ends of the chromosome.
Cat-eye syndrome is a rare disorder most often caused by a chromosomal change called an inverted duplicated 22. A small extra chromosome is made up of genetic material from chromosome 22 that has been abnormally duplicated (copied). The extra genetic material causes the characteristic signs and symptoms of cat-eye syndrome, including an eye abnormality called ocular iris coloboma (a gap or split in the colored part of the eye), small skin tags or pits in front of the ear, heart defects, kidney problems, and, in some cases, delayed development.
A rearrangement (translocation) of genetic material between chromosomes 9 and 22 is associated with several types of blood cancer (leukemia). This chromosomal abnormality, which is commonly called the Philadelphia chromosome, is found only in cancer cells. The Philadelphia chromosome has been identified in most cases of a slowly progressing form of blood cancer called chronic myeloid leukemia, or CML. It also has been found in some cases of more rapidly progressing blood cancers (acute leukemias). The presence of the Philadelphia chromosome can help predict how the cancer will progress and provides a target for molecular therapies.
And of course, none of these conditions are detected in me except for one minor "defect" (if you consider it abnormal at all) which is having large feet when down with 22q13 deletion syndrome. But obviously my speech is not delayed or absent, so I doubt I'm having such syndromes. (DO NOT QUOTE MENTAL RETARDATION!)
Thank god. =]
