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Concept: Sibling


Studies have suggested that number of siblings and birth order is associated with obesity. However, studies combining these exposures are needed. This study aimed at investigating obesity in children and young adults in regard to different combinations of family size and birth order.

Concepts: Family, Biology, Obesity, Child, Childhood, Cultural studies, Childhood obesity, Sibling


Offspring survival can often depend on successful communication with parents about their state of need. Theory suggests that offspring will be less likely to honestly signal their need when they experience greater competition from either a greater number of nestmates or less-related nestmates. We found support for this hypothesis with a comparative analysis, examining data from across 60 species of birds. We found that offspring are less honest about their level of need when (i) they face competition from current siblings; (ii) their parents are likely to breed again, and so they are in competition with future siblings; and (iii) parental divorce or death means that they are likely to be less related to future siblings. More generally, these patterns highlight the sensitivity of communication systems to conflict between signaler and receiver while also suggesting that when there is little conflict, natural selection favors the honest.

Concepts: Family, Natural selection, Parent, Signal, Sibling, Offspring, Parental investment, Divorce


Trichilemmal cyst, also known as “pilar cyst,” is a benign cyst containing keratin and its breakdown products with a wall resembling external root sheath of hair. It occurs mostly in females as a solitary firm nodule over scalp. Occurrence of multiple trichilemmal cysts in areas other than scalp is extremely rare. We are reporting a case of a 40-years-old female who presented with multiple calcified trichilemmal cysts in multicentric distribution associated with alopecia universalis. Similar complaints were present in elder sister of the patient, indicating a genetic background. Multicentric distribution of trichilemmal cysts, calcification, familial occurrence, and association with alopecia universalis seen in our case are all rare and intriguing features.

Concepts: Family, Female, Gamete, Sebaceous cyst, Cyst, Sibling, Trichilemmal cyst


When parents select similar sounding names for their children, do they set themselves up for more speech errors in the future? Questionnaire data from 334 respondents suggest that they do. Respondents whose names shared initial or final sounds with a sibling’s reported that their parents accidentally called them by the sibling’s name more often than those without such name overlap. Having a sibling of the same gender, similar appearance, or similar age was also associated with more frequent name substitutions. Almost all other name substitutions by parents involved other family members and over 5% of respondents reported a parent substituting the name of a pet, which suggests a strong role for social and situational cues in retrieving personal names for direct address. To the extent that retrieval cues are shared with other people or animals, other names become available and may substitute for the intended name, particularly when names sound similar.

Concepts: Family, Future, Parent, Sound, Substitute good, Sibling, Information retrieval


Findings from family and twin studies support a genetic contribution to the development of sexual orientation in men. However, previous studies have yielded conflicting evidence for linkage to chromosome Xq28. Method We conducted a genome-wide linkage scan on 409 independent pairs of homosexual brothers (908 analyzed individuals in 384 families), by far the largest study of its kind to date.

Concepts: Family, Gene, Gender, Gamete, Gender identity, Sexual orientation, Transgender, Sibling


National medical organizations recommend that during prenatal counseling sessions, healthcare providers discuss how having a child with Down syndrome (DS) might impact the family unit. Few studies, to date, have surveyed families about their life experiences. For this investigation, we examined 41 family attitudes, which were obtained from mailed questionnaires completed by 1,961 parents/guardians, 761 brothers/sisters, and 283 people with DS who were members of six DS non-profit organizations, chosen for their size, ethnic/racial diversities, and geographic distribution throughout the United States. About 83% of families reported to all being proud of the family member with DS, and 87% reported to all feeling love for the member with DS. Younger siblings (ages 9-11) were more likely to feel embarrassed by their sibling with DS if their parents/guardians also did. If one or more parents/guardians felt that their children without DS did have a good relationship with their child with DS, siblings were more likely to report that they loved and liked their brother/sister with DS. Overall, our data demonstrate that positive themes tend to dominate within modern-day families who have members with DS, although challenges were not insignificant for some. © 2015 Wiley Periodicals, Inc.

Concepts: Family, United States, Interpersonal relationship, Down syndrome, Love, Sibling, Non-profit organization, Federal Bureau of Investigation


This study examined differences in children’s psychological and social indicators in non-traditional families in Israel, focusing on fatherless families headed by lesbian mothers and single mothers by choice. Although Israel is considered an industrialized westernized country, centrality of the traditional nuclear family predominates this country.

Concepts: Family, Mother, Father, Sexual orientation, Sibling, Extended family, Nuclear family, Sociology of the family


Congenital insensitivity to pain is a rare hereditary sensory and autonomic neuropathy (HSAN). This disorder is an autosomal recessive condition: since 1996, mutations attributed to this entity have been found in the neurotrophin tyrosine-kinase gene receptor on chromosome 1. The authors report 3 cases of congenital insensitivity to pain. In these 3 sisters of consanguineous parents, the clinical investigation showed total absence of pain and temperature sensations with preservation of all other sensory modalities, mental retardation, but in contrast to HSAN type IV, there was no anhidrosis. The neurophysiological investigation revealed an isolated axonal sensory polyneuropathy in the 3 patients. The clinical and neurophysiological investigations were normal in both parents and the brother. The physiopathology of this entity is discussed. We suggest a particular form of HSAN type IV with preservation of transpiration or a new entity of congenital insensitivity to pain, which should be analyzed genetically.

Concepts: DNA, Genetics, Allele, Biology, Sensory system, Sibling, Neurological disorders, Congenital insensitivity to pain with anhidrosis


The practice of joint physical custody, where children spend equal time in each parent’s home after they separate, is increasing in many countries. It is particularly common in Sweden, where this custody arrangement applies to 30 per cent of children with separated parents. The aim of this study was to examine children’s health-related quality of life after parental separation, by comparing children living with both parents in nuclear families to those living in joint physical custody and other forms of domestic arrangements.

Concepts: Family, Marriage, Parent, Mother, Father, Sibling, Child custody, Divorce


PURPOSE: Cerebrotendinous xanthomatosis is a progressive neurodegenerative storage disease caused by recessive CYP27A1 mutations and is characterized by abnormal deposition of cholestanol and cholesterol in multiple tissues, including the lens and brain. Oral chenodeoxycholic acid is preventive and can be therapeutic, but is not used optimally because the condition typically is diagnosed late or not at all. When affected children demonstrate lens opacities, ophthalmologists have the unique potential to facilitate earlier diagnosis and treatment by recognizing the juvenile cataract phenotype. This study highlights the morphology of lens opacities in a family with genetically confirmed disease. DESIGN: Prospective case series. PARTICIPANTS: Four siblings and their 2 parents, who are first cousins. METHODS: Ophthalmic examination, general physical examination, and exome sequencing guided by homozygosity analysis. MAIN OUTCOME MEASURES: Ophthalmic findings, general clinical findings, and results of CYP27A1 candidate gene testing. RESULTS: Two sisters, each visually symptomatic before 10 years of age, had a unique pattern of bilateral fleck deposits throughout the lens with significant posterior capsular cataract. When initially examined at 8 years of age, their then-asymptomatic younger brother had the same bilateral fleck deposits with minimal posterior capsular opacity; 1 year later, he demonstrated anterior capsular opacity and became symptomatic. Both asymptomatic parents had few but distinct similar flecks localized at or near the anterior Y-suture, whereas an asymptomatic sister did not. Genetic analysis revealed homozygosity for a known CYP27A1 mutation (c.1263+1G→A) in the 3 symptomatic siblings, heterozygosity for the mutation in the 2 parents, and no mutation in the asymptomatic sister. When specifically questioned, the 3 affected children had experienced recurrent bouts of diarrhea in early childhood, which is a common feature of the disease. CONCLUSIONS: An unusual pattern of fleck lenticular deposits was seen in affected children. With time, capsular opacities (posterior only or posterior and anterior), developed and caused visual symptoms. Such juvenile lenticular findings should raise suspicion for this treatable metabolic disorder, especially when in the context of recurrent diarrhea during early childhood. Asymptomatic fleck-like opacities at or near the anterior Y-suture may be a carrier sign. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Concepts: Family, Genetics, Metabolism, Childhood, Ophthalmology, Physical examination, Sibling, Cerebrotendineous xanthomatosis