This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
[{'content': 'As regards to intraocular retinoblastoma, which one of the following statements is false – \nSelect and explain. \nA. 94% of cases are sporadic, B. Patients with sporadic retinoblastoma do not pass their genes to their offsprings, C. Calcification in the tumor can be detected on ultrasound scan, D. Reese–Ellsworth classification is useful in predicting visual prognosis following radiotherapy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Very important facts about sporadic retinoblastoma -\n\n\nIt is not inherited (not acquired from parents)\nBut it is heritable (1/3rd cases can transmit the gene to their offspring’s).\n\n\nUltrasound and CT scan are able to detect an intraocular mass with calcification which is pathognomonic of retinoblastoma.\nThe prognosis for preservation of the eye with at least some useful vision can be assessed with some degrees of success using classification such as Reese-Ellsworth system and the Esson prognosis classification.\n\nOption a is controversial\n\nDifferent textbook have mentioned different percentage for sporadic and hereditary retinoblastoma -\xa0"95% of these retinoblastomas has no family history". \xa0—Neonatal emergencies\n"The majority of retinoblastoma cases (90%) arise sporadically in the tissues of the affected proband or\xa0the parental germ line". ___\xa0Carlos\n"The great majority of retinoblastoma (85%) are sporadic tumors".\xa0— Eye pathalogy\n"The majority of retinoblastoma is sporadic (60%)". \xa0— Blue prints pediatrics\xa0\n"Nonheritable retinoblastoma accounts for about 60% of cases". -\xa0\xa0Tumors of the eye by H. cher\n"Non- hereditary or sporadic cases account for 60% of all cases". ___Khurana\n"60% of all retinoblastoma are sporadic".\xa0\xa0— Human heredity\n\n\n\nSo, some books have mentioned that 90-95% cases of retinoblastoma are sporadic. While others have mentioned that 60-65% cases of retinoblastoma are sporadic.\nTherefore, I had to do extensive work on this and found something to clear your doubts.\nMost of the books have considered sporadic cases and non- heritable cases as the same. Which is not the cases. I have read many books on genetics of retinoblastoma. First read the following statement\n\n"About 40% of all retinoblastoma patients have a germ line mutation in the Rb gene, although 7% have a positive family history. Therefore, most patients with heritable retinoblastoma are sporadic cases\xa0with new germ line mutation" .\xa0\xa0— Human heredity with InfoTech.\n\nTherefore, though the chances of gene transmission is more in hereditary retinoblastoma, most of the heritable retinoblastoma are sporadic (and this is the answer of our question).\nAfter reading this statement you can easily get the following facts-\n\n\nSporadic retinoblastoma are those in which there is no family history of retinoblastoma\nNon - hereditary cases are those in which the RB gene mutation is not acquired from parents\nHereditary cases are those in which the RB gene mutation is acquired from parents (this also includes heritable sporadic cases).\n\n\nThus, sporadic retinoblastoma and non - hereditary retinoblastoma are not synonymous :-\n\n\nSporadic cases = Nonhereditary cases + Hereditary cases with no positive family history of retinoblastoma.\n\n\nAfter reading all these you can easily understand that the percentage of sporadic retinoblastoma will always be more than non- hereditary retinoblastoma. Now you read the frequencies :-\n\n\nHereditary cases\xa0\xa0→\xa040% of all retinoblastomas\nNon-hereditary cases\xa0→\xa060% of all retinoblastomas\nSporadic cases\xa0→\xa090-95% of all retinoblastomas', 'role': 'assistant'}]