Terminal deletions in the short arm of chromosome one are generally associated with characteristic phenotype with dysmorphic features, including congenital anomalies and mental retardation with various degrees. Different outcomes depend on the sizes and locations of the deleted areas characterized by moderate to severe intellectual disability, delayed growth, hypotonia, seizures, limited speech ability, malformations, hearing and vision impairment and distinct facial features. The symptoms may vary, depending on the exact location of the chromosomal deletion but not a single reported case showed any ‘feature of anemia’.
We report here one male and one female individual with partial deletions on chromosome no. one, both at 1p36 region. Cytogenetic analysis of blood lymphocytes was studied with high resolution GTG-banding analysis, using cyto-vision software on their chromosomes. Results revealed 46, XY, del(1)(p36.21) in the male who was also diagnosed as a ‘beta thalassemia trait’ and the other case was 46, XX, del(1)(p36.3) in the female who was diagnosed as a case of ‘HbE-beta thalassemia’.
This report provides additional cases to the growing literature.
Deletion 1p36 is the most common terminal deletion syndrome with an estimated occurrence of 1:5000 live births. We report two patients with 1p36 deletions among which one shows ‘atypical’ proximal interstitial deletion at 1p36.21 using HR-GTG banding analysis. Interestingly, both the patients manifest one extra clinical characteristic that is different from those seen in ‘classical’ monosomy 1p36 syndrome, is ‘microcytic anemia’.
Based on the analysis of the clinical and molecular data from our patients and those reported in the literature, we suggest that deletion 1p36.21 chromosomal abnormality may constitute yet another deletion syndrome distinct from the classical distal 1p36 deletion syndrome.
Our aim was to find out further information regarding anemia since there are previously reported cases of anemias associated with this 1p36 region—one is presence of a ‘putative tumor suppressor gene’ important in the evolution of chronic myelocytic leukemia and the other is one inherited erythroblastopenia, commonly known as ‘Diamond-Blackfan anemia’ (DBA), caused by mutation in the gene encoding ribosomal protein L11 (RPL11) to answer families’ questions in the clinical setting.
Materials and methods
Standard cytogenetic analysis was used with high resolution GTG-banding analysis, using cytovision software for karyotyping and high performance liquid chromatography (HPLC) and amplification refractory mutation mutation system (ARMS-PCR) to detect the five common Indian b-thalassemia mutations: [IVS-I-5 (G >C), Cod 15 (G-A), Cod 8/9 (+G), Fr 41/42 (–TTCT) and Cod 26 (G-A)].
Results showed 46, XY, del(1)(p36.21) in the male, additionally diagnosed as a ‘beta thalassemia trait’ and in another case 46, XX, del(1)(p36.3) in female who was diagnosed as a case of ‘HbE-beta thalassemia’.
These two patients with deletion 1p36 represent association with other genetic disorder which is characterized by hematological abnormalities.
How to cite this article
De P, Chakravarty S, Chakravarty A. 1p36 Deletions in Two Cases with Thalassemia. Int J Infertil Fetal Med 2014;5(2):69-74.