The pattern of invasive lobular carcinoma in the patients diagnosed with breast cancer from Balochistan.

INTRODUCTION: Invasive lobular carcinoma (ILC) is the second most common type of breast cancer accounting for 5%-15% of all the breast cancer cases. The present study was performed on 171 breast cancer patients from Balochistan registered in CENAR (Center for Nuclear Medicine and Radiotherapy), Quetta. MATERIALS AND METHODS: Written consent was obtained from the patients. The history of the disease was taken from the patients, and the patients' enrollment files were retrieved. RESULTS: Of the 171 patients, 5 (2.96%) were diagnosed with ILC with tumor Grade II, and stage of the cancer reported was Grade III in all the 5 patients affected with ILC. CONCLUSION: ILC is the second most common type of breast cancer diagnosed with comparatively lower grade but almost reported infiltrating.

Mutational spectrum of the TYR and SLC45A2 genes in Pakistani families with oculocutaneous albinism, and potential founder effect of missense substitution (p.Arg77Gln) of tyrosinase.

BACKGROUND: Oculocutaneous albinism (OCA) is an autosomal recessive disorder of abnormal melanin formation, which results in hypopigmentation of skin, hair and eyes. OCA is classified into four types based on clinical and genetic findings. OCA1 is the most severe form of albinism, and is caused by mutations in the tyrosinase (TYR) gene, while OCA4 is caused due to mutations in SLC45A2. METHODS: In total, 13 families with ≥ 3 members with OCA were enrolled. Family history was ascertained and pedigrees were drawn up. Blood samples were collected and processed for DNA extraction. Linkage analysis was performed by typing three short tandem repeat markers in candidate regions of TYR and SLC45A2. Sequence analysis was performed of all the coding exons and adjacent intronic sequences of both genes. RESULTS: Eight families showed linkage to OCA1 and one family showed linkage to OCA4. Four missense substitutions (p.Arg239Trp, p.Ser192Tyr, p.Ser44Arg and p.Arg77Gln) were identified in TYR in the families with OCA1 linkage, and another missense substitution (p.Gln272Lys) was identified in the family with OCA4 linkage. One of the identified missense substitution (p.Arg77Gln) in TYR was found in five different families, which had a common haplotype. CONCLUSIONS: We identified four missense substitutions in TYR and a single missense substitution in SLC45A2. One missense substitution (p.Arg77Gln) in TYR was found in five different families that originated from the same geographical area and displayed a common haplotype, suggesting a single origin that then spread to different geographical areas of Azad Kashmir, Pakistan.

Origin of Plasmodium falciparum malaria is traced by mitochondrial DNA.

The origin and geographical spread of Plasmodium falciparum is here determined by analysis of mitochondrial DNA sequence polymorphism and divergence from its most closely related species P. reichenowi (a rare parasite of chimpanzees). The complete 6 kb mitochondrial genome was sequenced from the single known isolate of P. reichenowi and from four different cultured isolates of P. falciparum, and aligned with the two previously derived P. falciparum sequences. The extremely low synonymous nucleotide polymorphism in P. falciparum (pi=0.0004) contrasts with the divergence at such sites between the two species (kappa=0.1201), and supports a hypothesis that P. falciparum has recently emerged from a single ancestral population. To survey the geographical distribution of mitochondrial haplotypes in P. falciparum, 104 isolates from several endemic areas were typed for each of the identified single nucleotide polymorphisms. The haplotypes show a radiation out of Africa, with unique types in Southeast Asia and South America being related to African types by single nucleotide changes. This indicates that P. falciparum originated in Africa and colonised Southeast Asia and South America separately.