Turner syndrome with ring x chromosome: do they have a distinct phenotype?

In contrast to classic Turner syndrome, Turner patients with ring X chromosome are associated with distinct dysmorphism and are likely to be mentally impaired. Four Turner patients with ring X chromosome were examined for phenotypic features of Turner syndrome and additional dysmorphism. Both patients 1 and 2 are twins with normal intelligence whereas patients 3 and 4 have mental impairment. With the exception of patient 4, the other three patients only have few Turner characteristics. None of the patients have the distinctive dysmorphism previously reported in Turner syndrome with ring X chromosome. Both twins developed spontaneous puberty. Patients 3 and 4 however had no spontaneous puberty. We postulate that this variation may be related to the ring size, the proportion of 45,X and ring X chromosome in cell lines of various body tissues as well as the ability of these rings to be inactivated as a result of lyonisation

Trisomy X and myelodysplastic syndrome (MDS) with eosinophilia

We reported a young patient with myelodysplastic syndrome (MDS) with eosinophilia, in which her chromosomal analysis revealed the presence of trisomy X and a marker chromosome at chromosome 11. The technique used to detect the chromosomal abnormalities is a multicoloured –fluorescent in situ hybridization technique (M-FISH). Our observation suggested that these underlying chromosomal abnormalities were probably responsible for her development of MDS with eosinophilia. Myelodysplastic syndrome (MDS) is a condition whereby there is ineffective production of haematopoietic stem cells and poor quality of cells produced. The cause can either be a primary bone marrow problem, de novo or therapy related. Most MDS cases are secondary rather than primary. Many chromosomal abnormalities have been found in cases of myelodysplastic syndrome. We described a case of MDS with eosinophilia in association with presence of trisomy X and a marker chromosome in chromosome 11

A rare case of a male infant with down-turner syndrome and review of cases

Individuals with double aneuploidy of Down-Turner syndrome are very rare and to date, fewer than 50 cases have been reported, worlwide. We report a case of a male infant who presented with dysmorphic features of upslanting eyes, flat nasal bridge, wide spaced nipples and macroglossia. Based on the clinical features, he was diagnosed with Down syndrome. His peripheral blood sample was taken and sent for cytogenetic analysis for confirmation. Chromosome analysis of his lymphocyte cell culture revealed a mosaic pattern of double aneuploidy with monosomy X identified in 31 metaphases and trisomy 21 in 14 metaphases: (45,X[31]/47,XY,+21[14]). Further analysis with fluorescence in situ hybridization (FISH) using Vysis LSI SRY Spectrum Orange/CEP X Spectrum Green Probe and Vysis CEP Y Spectrum Aqua Probe and Vysis LSI 21 Spectrum Orange Probe performed on the cells (nuclei and metaphases) has confirmed the presence of the abnormal two cell lines (81% monosomy X and 19% trisomy 21) in the patient. Ultrasound investigations of his pelvic region showed normal testes and no evidence of uterus, ovary or vagina. To the best of our knowledge, this is the first Down-Turner syndrome reported in Malaysia. In conclusion, this case demonstrates the importance of Giemsa-banded karyotype and FISH analyses as diagnostic tools in identifying the chromosomal abnormality and determining the ratio of the normal:abnormal cells present in the patient. An annotated bibliography of earlier reported cases of Down-Turner with documented karyotyping is also included in this report

Eccentricity of Acute Myeloid Leukemia with NPM1 and FLT3-ITD mutation: a case report

Acute myeloid leukaemia (AML) is the most prevalent type of acute leukaemia in adults, with a heterogenous cytogenetics landscapes. NPM1 mutated AML was designated as a provisional entity in 2008 World Health Organisation (WHO) Classification of Tumours of Haematopoietic and Lymphoid Tissues. In 2017, fourth edition was revised and AML was recognised as a distinct entity with distinctive cytological, molecular and clinicopathological features. For example, AML with NPM1 mutation is strongly associated with acute myelomonocytic and acute monocytic leukemia. In recent studies, AML with both NPM1 and FLT3- ITD mutations, had been associated of blasts with cup-like nuclei. We described this characteristical morphology in a 68-year-old female who was diagnosed with AML alongside NPM1 and FLT3-ITD mutation. She presented with a short history of fever and laboratory findings of hyperleukocytosis, mild anemia and thrombocytopenia. A diagnosis of AML was proposed from the cytological and flow cytometry examinations. The full blood picture and bone marrow aspirate showed some of the blasts with cup-like nuclei and the flow cytometry examination showed characteristical feature which was suggestive of AML with NPM1 mutation. Polymerase chain reaction (PCR) detected mutation in FLT3-internal tandem duplication (ITD) and NPM1. This patient was treated with AML protocol but succumbed due to sepsis. This case highlighted the importance of recognising this clinicopathological presentations to provide rapid diagnosis and guide for the appropriate molecular testing. In this study, new treatment modalities available for this type of AML and literature review of previous studies were also discussed

Detection of BCR-ABL T315i mutation in imatinib resistant chronic myeloid leukemia patients

Chronic myeloid leukemia (CML) patients who have BCR-ABL T315I mutation, usually present in the advance phase of the disease with overall survival (OS) shorter than those without the mutation. This study aimed to determine the prevalence of T315I mutation amongst imatinib mesylate (IM) resistant CML patients and to compare the OS between T315I-mutated and non-T315I-mutated patients. Sixty consecutive CML patients who were treated with IM for at least 18 months and their treatment responses, were recorded. The mutation analysis was done using allele-specific oligonucleotide reverse transcriptase-polymerase chain reaction (RT-PCR) assay followed by direct sequencing technique. Forty-two patients (70%) were found to have IM-resistance. Five out of 42 patients had detectable T315I mutation. Median OS of IM-resistant T315I-mutated patients was 96 months (95% CI:54-138) compared to 84 months (95% CI:48-120) in non T315I-mutated patients, although this was found to be statistically insignificant (p = 0.43). The present study showed a higher prevalence of T315I mutation as compared to a few local studies. Median OS of T315I-mutated patients were observed to be longer than non-T315-mutated patients. Further studies encompassing larger cohort of patients are required to confirm this finding

Utility of Ki-67 and p53 in distinguishing cervical intraepithelial neoplasia 3 from squamous cell carcinoma of the cervix

The differentiation between cervical intraepithelial neoplasia 3 (CIN 3) and early squamous cell carcinoma (SCC) of the cervix may be difficult in certain situations. Identification of invasion beyond the basement membrane is the gold standard for the diagnosis of the latter. The objective of this study was to determine whether the use of Ki-67 and p53 could help in solving the above dilemma. This was a retrospective study on 61 cases of cervical neoplasms comprising of 25 cases of CIN 3 and 36 SCC. All cases were evaluated by immunohistochemistry using Ki-67 and p53 monoclonal antibodies. Results showed that the differences of Ki-67 and p53 expression between CIN 3 and SCC were statistically significant. In conclusion, Ki-67 and p53 may serve as helpful adjuncts to routinely-stained histological sections in differentiating between CIN 3 and SCC

Mutations in KIF27, GNAS and IFT140 genes in a patient with VACTERL association: a case report

VACTERL association is a rare genetic disorder involving at least three of the following congenital malformations: vertebral defects (V), anal atresia (A), cardiac defects (C), trachea-oesophageal fistula with or without oesophageal atresia (TE), renal anomalies (R) and limb abnormalities (L). Until now, the aetiology of VACTERL association is unknown, particularly at the molecular level. Here, we performed whole exome sequencing (WES) of an infant with VACTERL association. The patient was delivered prematurely at 30 weeks and had 4/6 of the VACTERL malformations. Trio-WES analysis was performed using Torrent Suite and ANNOVAR. Polymorphisms with an allele frequency of >0.01 were excluded, and the remaining variants were filtered based on de novo mutations, autosomal recessive, X-linked and di-genic inheritance traits. In this patient, no homozygous, compound heterozygous or X-linked mutations was associated with VACTERL. However, we identified two heterozygous mutations; KIF27 (ENST00000297814: c.3004A> C:p.N1002H) and GNAS (ENST00000371098: c.205C>A:p.H69N) genes that were inherited from her father and mother respectively. A de novo, IFT140 gene mutation (ENST00000426508: c.683C>G:p.S228C) was also identified in this patient. The VACTERL phenotype in this patient may due to heterozygous mutations affecting KIF27 and GNAS genes, inherited via autosomal recessive trait. In addition, the IFT140 gene mutation may also be involved. These genes are known to be directly or non-directly involved in the sonic hedgehog signalling that is known to be implicated in VACTERL. This is the first report of these genetic mutations in association with VACTERL

Molecular cytogenetics and genetic characterisation of chromosomal rearrangements

In this thesis I report three related studies that utilise state-of-the-art technologies to investigate germline and somatic chromosomal rearrangements in humans. Firstly, 16 patients with cytogenetically detectable deletions of 3p25-p26 were analysed with high density single nucleotide polymorphism (SNP) microarrays; Affymetrix 250K SNP microarrays (n=14) and Affymetrix SNP6.0 (n=2). Assuming complete penetrance, a critical region for congenitalheart disease (CHD) susceptibility gene was refined to approximately 200 kb and a candidate critical region for mental retardation was mapped to ~1 Mb interval containing SRGAP3. Secondly, I used SNP microarray and molecular cytogenetic studies to characterize chromosome 11p15 in 8 patients with the imprinting disorder Beckwith-Wiedemann syndrome (BWS). In addition to characterising 11p duplications in three patients, the breakpoints in two patients with balanced rearrangements were mapped to two distinct regions. Thirdly, I used high resolution SNP arrays (Affymetrix 250K Sty1 and 6.0 arrays) to identify copy number changes in renal cell carcinoma (RCC) primary tumours (n=81) and cell lines (n=23). Copy number changes most frequently involved large segments (>10Mb) and loss of 3p and gain of 5q were the most common copy number changes. A comparison of copy number changes in RCC cell lines and inherited and sporadic primary tumours was made

The role of conventional and molecular cytogenetics in the diagnosis of microdeletion syndromes

In this report we demonstrate the role of fluorescence in situ hybridisation (FISH) and conventional cytogenetic methods in clinically and cytogenetically confirmed cases of microdeletion syndromes. A total of nine cases were referred to the Cytopathology and Cytogenetic Unit, Hospital Universiti Kebangsaan Malaysia (HUKM) from 2002 to 2004. They include three Prader-Willi syndrome, three DiGeorge syndrome, one Williams syndrome, one Miller-Dieker syndrome and one Kallmann syndrome. Blood samples from the patients were cultured and harvested following standard procedures. Twenty metaphases were analysed for each of the cases. FISH analysis was carried out for all the cases using commercial probes (Vysis, USA): SNRPN and D15S10 for Prader-Willi syndrome, LIS1 for Miller Dieker syndrome, ELN for Williams syndrome, KAL for Kallmann syndrome, TUPLE 1 and D22S75 for DiGeorge syndrome. Conventional cytogenetic analysis revealed normal karyotypes in all but one case with structural abnormality involving chromosomes 9 and 22. FISH analysis showed microdeletions in all of the nine cases studied. This study has accomplished two important findings ie. while the FISH method is mandatory in ruling out microdeletion syndromes, conventional cytogenetics acts as a screening tool in revealing other chromosomal abnormalities that may be involved with the diseas