Karyotype Analysis of a Patient: Genetic Disorder and Treatment Options

This paper evaluates the case study of a six-month-old baby who has shown ambiguities in her normal development process. It discusses the genetic disorder that the baby is suffering from based on karyotype analysis and explores the available treatment options.

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Sender’s Name,
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Recipient’s organization name,
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Subject: Karyotype analysis of the patient
Dear (enter recipient’s name),
New born screening can be defined as the procedure of testing new born babies for the
presence of any potential genetic disorder or congenital anomalies. New born screening also
referred to as (NBS) is generally performed with a small amount of the blood sample collected
from the new born. It should be mentioned in this context that the presence of genetic disorders
within new born babies are rare, however, early diagnosis and detection of the disorders makes
the treatment procedure convenient. This paper intends to evaluate the case study of a six month
old baby who has shown ambiguities in her normal development process. The paper would
further analyze the genetic disorder that the baby is suffering from on the basis of karyotype
analysis and discuss the available treatment options for the baby.
A karyotype is ideally a pictorial representation of the 23 pairs of chromosome present
within a cell. Karyotyping is a form of new born screening that helps in the detection of

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congenital anomalies within the baby. The karyotype testing also serves as a confirmatory test of
Leukemia. It should be noted in this context that karyotyping is also advised during the
pregnancy which forms a part of the Pre-natal screening test (PNS) and it helps in the detection
of the genetic disorder that the baby might be suffering from during the course of pregnancy. The
sampling procedure for karyotyping is different for NBS and PNS. While, blood sample is
commonly used for karyotyping (NBS), PNS makes use of the chorionic villus sampling (Singh
2015).
Humans contain 23 pairs of chromosome which is inherited from the father and the
mother and totals up to 46 chromosomes. 22 pairs are referred to as the autosomes that are
responsible for carrying out the physiological functioning of the body while the 23rd pair refers to
the sex chromosome. The genetic constitution of XX refers to a female whereas that of XY refers
to a male. It is crucial to note here that an error in the process of genetic coding leads to the
impairment of normal physiological functioning and gives rises to genetic disorders. A karyotype
helps in the identification of genetic disorders. These chromosomal defects generally occurs
during the fetal development at the time of meiosis (division of the reproductive organs) or
mitosis (division of organs other than the reproductive organs).
A karyotype helps in the characterization of the chromosomes on the basis of the shape,
number or the size and can potentially identify both the structural as well as the numeric defects.
Numerical abnormalities are also referred to as addition of multiple chromosomes or the lack of
certain chromosomes. On the other hand, structural abnormalities refer to a wide number of
conditions that include, deletions, translocations, inversions or duplications. Deletions refer to
the condition where a part of the chromosome is missed out during the division process. On the
other hand, translocation refers to the condition where a part of one chromosome attaches to the

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short arm or long arm of another chromosome. Inversions refer to the condition where a
chromosome is flipped in the opposite direction and duplication refers to condition when a
chromosome is accidentally copied.
Fig: Karyotype of patient
In this case the patient is a 6 month old female baby who has exhibited a distinct
developmental delay. The baby had been delivered by C-section after an uneventful pregnancy
but has not yet reached the development milestone of a social smile. The body weight of the
infant is extremely low (~<3% percentile for the age of girls) on account of feeding difficulties.
Also, the head circumference has been reported to be around 34 cm (~ <5%). On the basis of the
karyotype analysis, it can be said that the baby is supposedly suffering from Cri-du-Chat
syndrome. Cri-du-chat syndrome is a rare genetic disorder and occurs due to the deletion of the p

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arm of the fifth chromosome (5p-). Research studies reveal that Cri-du-chat syndrome is not
inherited from the parents but manifests in the baby due to the deletion of the P arm of the 5th
chromosome (Chen and Chen 2016). It is further believed that the deletion leads to a loss of
number of essential genes that are responsible for carrying out the normal developmental
process. It should be critically noted in this regard, that the loss of the CTNND2 gene from
chromosome 5 leads to intellectual disability in individuals (Gu et al. 2013). The genetic
condition is characterized by delayed development, microcephaly (small head size), extremely
lower birth weight and weak muscle tone. In addition to this, the external symptoms of the
syndrome include a set of distinct facial features such as rounded face, small jaw, widely set eyes
and low set ears (Nguyen et al. 2015). The diagnosis of the syndrome is done on the basis of
genetic testing along with the consideration of the developmental process. Scientific studies
suggest that the symptoms appear prominently from birth up to the age of 6 months. The main
symptoms of the syndrome include the condition of microcephaly (head too small) and a high-
pitched cry that makes the baby cry like a cat. Symptoms with motor disabilities have also been
observed in patients with Cri-du-chat syndrome (Elmakky et al. 2014). Other symptoms also
include feeding problems where the baby experiences difficulty in swallowing or sucking (Hong
et al. 2013). With the advancing age Patients suffering from Cri-du-Chat syndrome also exhibit
intellectual disability, appearance of prominent supraorbital ridges, hypoplastic nasal bridge and
problems related to scoliosis. The exact mechanism of the pathophysiology of this genetic
disorder remains unknown, however the deletion is believed to be de-novo deletion. There is no
cure for the genetic disorder, however a number of support options are available that can help in
controlling the intensity of the symptoms. According to the case scenario the baby’s head
circumference should be equivalent to 45.72 cm or approximately 18 inches and the body weight

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should have been double to that of the body weight detected at birth. The baby also exhibits
problem with hand movement and experiences feeding difficulties. The karyotype analysis also
suggests chromosomal aberration (deletion) within the P arm of the 5 chromosome. Therefore, it
is likely, that the baby is suffering from Cri-du-Chat syndrome. However, the case study does not
mention about the distinct cat-like cry of the baby.
There is no standard treatment available for the cure of this syndrome, however a number
of support services are available that can help in improving the symptoms. It is advised that the
child must continue the support therapies throughout her life.
The baby must be provided good nutrition and her weight should be stringently
monitored by a pediatric dietician. In addition to this, referral to a speech therapist and
occupational therapist could help in supporting the baby through the delayed developmental
process. However, studies suggest that babies affected with Cri-du-chat syndrome can expect to
lead a normal life expectancy. It can be expected that the development of the baby would be
delayed in comparison to normal babies.
It is important to note here that the case study has only provided information about the
head circumference and the body weight of the baby. The karyotype result though provided is
not sufficient for the accurate detection of the disorder. A number of cases have been reported
where the karyotype analysis had misled the detection of the correct genetic disorder. A number
of improved NBS screening tests such as microarray could help in accurately diagnosing the
disorder. The case study vitally focuses on two important symptoms that include microcephaly
and lower body weight. The symptoms could also result due to an inherited mutation from the
parents. This could only be confirmed after comparing the karyotype of the parents. Therefore,

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advanced NBS screening such as 2-step testing and microarray can help in the accurate detection
of the disorder within the baby.
Thus to conclude, it can be mentioned that the primary intervention goal for the treatment
of the baby would include proper nutrition and availing support services. Also, the parents of the
baby would be educated about the medical disorder and offered counseling to help them walk
through the disorder and the support options available. Further, the parents would also be
recommended an advanced NBS testing for the accurate detection of the disorder.
Yours sincerely,
Signature
(Name of the sender)

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References:
Chen, H. and Chen, H., 2016. Cri-du-chat syndrome. Atlas of Genetic Diagnosis and Counseling,
pp.1-9.
Elmakky, A., Carli, D., Lugli, L., Torelli, P., Guidi, B., Falcinelli, C., Fini, S., Ferrari, F. and
Percesepe, A., 2014. A three-generation family with terminal microdeletion involving 5p15. 33–
32 due to a whole-arm 5; 15 chromosomal translocation with a steady phenotype of atypical cri
du chat syndrome. European journal of medical genetics, 57(4), pp.145-150.
Gu, H., Jiang, J.H., Li, J.Y., Zhang, Y.N., Dong, X.S., Huang, Y.Y., Son, X.M., Lu, X. and
Chen, Z., 2013. A familial Cri-du-Chat/5p deletion syndrome resulted from rare maternal
complex chromosomal rearrangements (CCRs) and/or possible chromosome 5p
chromothripsis. PLoS One, 8(10), p.e76985.
Hong, J.H., Lee, H.Y., Lim, M.K., Kim, M.Y., Kang, Y.H., Lee, K.H. and Cho, S.G., 2013.
Brain stem hypoplasia associated with Cri-du-Chat syndrome. Korean journal of
radiology, 14(6), pp.960-962.
Nguyen, J.M., Qualmann, K.J., Okashah, R., Reilly, A., Alexeyev, M.F. and Campbell, D.J.,
2015, September. 5p deletions: current knowledge and future directions. In American Journal of
Medical Genetics Part C: Seminars in Medical Genetics (Vol. 169, No. 3, pp. 224-238).
Singh, M., 2015. CARE OF THE NEW BORN REVISED 8ED (2017). CBS Publishers &
Distributors Private Limited.

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Zhang, B., Lu, B.Y., Yu, B., Zheng, F.X., Zhou, Q., Chen, Y.P. and Zhang, X.Q., 2017.
Noninvasive prenatal screening for fetal common sex chromosome aneuploidies from maternal
blood. Journal of International Medical Research, 45(2), pp.621-630.