Asian Journal of Case Reports in Medicine and Health 2(4): 1-9, 2019; Article no.AJCRMH.53879 A Genetically Transmitted, Benign Habit: A Case Report and Review A. S. V. Prasad1* 1Department of Internal Medicine, G.I.T.A.M, Rishikonda, Visakhapatnam, India. Author’s contribution The sole author designed, analysed, interpreted and prepared the manuscript. Article Information Editor(s): (1) Dr. Ayhan Goktepe, Professor, Department of Geodesy and Photogrammetry, Selcuk Universitesi, Teknik Bilimler MYO, Kampus, Turkey. (2) Dr. Arun Singh, Professor, Department of Community Medicine, Rohilkhand Medical College and Hospital, Bareilly, Uttar Pradesh, India. Reviewers: (1) Josef Finsterer, Rudolfstiftung, Austria. (2) Virginia Sánchez Monroy, Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía (Escuela Nacional de Medicina y Homeopatía), Mexico. (3) Bhaskar Sharma, Suresh Gyan Vihar University, India. Complete Peer review History: http://www.sdiarticle4.com/review-history/53879 Received 10 November 2019 Accepted 13 January 2020 Case Report Published 21 January 2020 ABSTRACT Habits are defined as acquired, repetitive, involuntary and body focused, stereotyped motor acts. Tics have the same attributes, but are characterised by muscle spasm additionally. So far, the emphasis in the literature is that the habits are acquired. There is no reference in the literature as to the habits being transmitted genetically. Whereas in the case of tics, some like, Tourette Syndrome (TS), are accepted to have genetic basis Habits are harmless. But some are self - destructive Out of the group of the four destructive habits, like trichotillomania (TTM), bruxism, scabiomania or skin pulling (SP) and onychophagia, TTM, along with chronic persistent motor tics, persistent vocal tics and combined motor and vocal tics like TS, are grouped together, as habit disorders by the American Psychiatry Association (APA) Statistical Manual of Mental Disorders classification, 4th edition (DMS 4). Virginia Commission recommends inclusion of SP also under habit disorders. Other authors include all the four destructive habits under the habit disorders. It is also accepted that habits are related to behavioural patterns and that the behavioural patterns are genetically determined. Thus an indirect link is established between the habits and heredity, through behaviours. The author presents in this article, a benign, ‘nose rubbing habit’ being transmitted through 6 generations in a family tree. Unique to the pattern of inheritance, 100 % desendents in _____________________________________________________________________________________________________ *Corresponding author: E-mail: [email protected]; Prasad; AJCRMH, 2(4): 1-9, 2019; Article no.AJCRMH.53879 some generations (generations 1,2 and 3) with involvement of both males and females, without any skip generations, is seen .Very early onset is recorded at the age as low as 2 years and as high as 6 years belonging to the in the 6th generation. This is the first of it’s kind reported in literature that a benign habit is shown to run in a family, across 6 generations. This is contrary to the popular belief, that habits are always acquired. If it is so, what is it that irrefutably transmitted through 6 generations in this case? Mitochondrial gene (mtDNA) transmission, involving recombinant maternal and paternal mtDNA, is suggested, by inference and after eliminating the other Mendalean and non Mendalean types of inheritance. Of course, the main intended focus of the article is to highlight the transmission of a habit- trait (?) genetically. As a possible explanation of this observed phenomena only, the tentative inheritance pattern is suggested. The matter is open for discussion by the concerned fraternity. Keywords: Habits; tics; habit disorders; mitochondrial inheritance; tourette syndrome. 1. INTRODUCTION is suggested by the view that "the relationship between the genes and behavior can change 1.1 Can a Habit be Transmitted over time as one has new experiences. In some Genetically? situations, genes play a larger role in determining one’s behavior; in other situations, environment At the very outset, the question appears plays a larger role in influencing your behavior superfluous, if not rediculous. Such cynicism, [9]. If the fact, that the habits are but stems from the well entrenched notion in the manifestation of certain behavioural patterns, literature, that the habits are acquired .Even the and the behavioural patterns have genetic basis, online Webster’s dictionary assumes so, when it the possibility of acquiring at least, some habits defines habit. (vide infra) At least, there is by genetic inheritance, becomes more obvious. consensus that the habits are related to With this background, this article presents a behavioural patterns. To cite a few such family lineage, in which a benign, nose rubbing opinions, “the habit is an automatic and rigid habit, is traced through six generations. Such pattern of behavior."(behavioural economic.com) continuous unbroken chain of transmission over “Habits are self-sustaining patterns of generations can’t be coincidental, as the author sensorimotor behaviour” [1]. The connection asserts. A possible type of inheritance is between the behaviour and genetics is suggested by a process of inference and established in the recent literature, as seen by elimination of different types of inheritance. But umpteen number of articles published in this the primary aim of this article is to objectively regard. As early as the nineteenth century, break the myth, that the habits are acquired only, Francis Galton, (a cousin of Charles Darwin), notwithstanding the fact, that it would be an uphill systematically studied behavior and heredity [2]. task It is held “that the behavior is determined by a combination of inherited traits, experience, and 1.2 Habits vs Tics the environment”. One more step forward is the view that “Some behaviors, called innate, comes Merriam-Webster’s online dictionary defines from our genes, but other behaviors are learned, habits as: "an acquired mode of behavior that either from interacting with the world or by being has become nearly or completely involuntary. “A taught" [3]. The dawn of a new branch of habit is defined as a way of behaving that is science- the "Behavioral genetics examines the repeated so often it no longer involves conscious role of genetic and environmental influences on thought”. The other definitions explicitly behavior [4]. It is now generally believed, that the implicating their genetic basis are broached human behavior is determined by complex above. They are characterized by being interactions of both nature and nurture" [5]. How repetitive and involuntary and some are motor genetics does affect the behaviour is summed up acts, habitually repeated. “A motor habit is a in the statement that "Behavior can influence habit which involves movement." (Psychology genetic expression in humans and animals by dictionary). For example, rubbing of the nose. activating or deactivating genes [6,7,8]. This Habit is more of a behavior or practice. Biologic interrelationship between the behaviour and and environmental factors are considered genetics is not necessarily be rigid and universal responsible for habit formation. 2 Prasad; AJCRMH, 2(4): 1-9, 2019; Article no.AJCRMH.53879 Some habits are destructive while others are are typified by repetitive body focused harmless. The former constitute a separate behaviours and include trichotillomania, skin group, named, "Habit disorders". Some of the picking, nail biting. recognised examples of the either type are listed below. 1.3 Childhood Habits and Ticks Harmless, nondestructive habits: Tics are common in children. They are usually Nose picking benign. Any of the motor habits/tics or vocal tics (but not both) described, may be involved. They Nose rubbing may last for less than one year or in any case not beyond adolescent period. They are typically Nose pinching transient tic disorders (renamed as provisional tic disorder). The American Academy of Child and Ear pulling Adolescent Psychiatry states that tics affect up to 10 percent of children during their early school Shoulders shrugging and Eye brows raising, etc. years. Over years, they outgrow their habits/ tics. It is also true that TS, a pathological entity also Destructive, impulsive habits: begins in childhood, a fact that should not be lost sight of. (Termed as Habit Disorders) 1.4 Habits and Tics, Do They Represent A Trichotillomania, (hair pulling) Spectrum? Bruxism, (teeth grinding) Both, habits and tics have more in common than in what they differ. for instance, both are Onychophagia,(nail biting) repetitive and involuntary and some are persistent. Only the presence (tic) or absence Scabiomania (skin pricking) (habit) of muscle spasm makes the difference. The Virginia Commission on youth behaviour There seems to be a consensus among includes both the Tic disorders (TD) and body researchers that TD and TS share enough focused habit disorders like nail biting, skin common aspects to be considered on a pulling (SP) and trichotillomania (TTM) under a continuum of severity. single umbrella", "the habit disorders". “The Commission foresees a common entity, from A tic is an involuntary, repetitive contraction of which both tics and habits. might diverge” .The certain muscles A tic is an uncontrolled sudden, APA (American Psychiatric Association) has repetitive movement(motor tics) or sound (vocal), included the habit disorder TTM,