Dermatoglyphic profile in 22q deletion syndrome

Abstract

A genetic subtype of schizophrenia has been described in 22q11 Deletion syndrome. Previous studies have described an excess of dermatoglyphic alterations in schizophrenia, such as low a-b ridge counts (ABRCs), a high frequency of ridge dissociations, and increased dermatoglyphic fluctuating asymmetry. Little is known however, about the dermatoglyphic profile of 22qDS subjects showing psychotic symptoms and its similarity to the previously reported anomalies in schizophrenia. We studied the palmar dermatoglyphics of 22 subjects with 22qDS of predominantly Caucasian origin, 15 of whom had psychotic illness, and in 84 healthy controls of similar ethnicity. We observed higher values for total ATD angle in cases than in controls (P = 0.04). In addition, there was an excess of radial figures in the hypothenar area in cases, especially in the left hand. Interestingly, greater fluctuating asymmetry, determined by the absolute difference between right and left ABRC, was observed in 22qDS subjects compared to controls (P = 0.05). However, no differences were found for ABRCs and frequency of dissociations. Despite the small sample size, the palmprints analyzed suggest the existence of an altered dermatoglyphic profile in 22qDS, involving: (i) ATD angle amplitude, (ii) presence of radial loops in the hypothenar area, and (iii) an increment of fluctuating asymmetry. The first two features are similar to those found in other genetic syndromes associated with low IQ, while high levels of fluctuating asymmetry have often been reported in schizophrenia.Chromosome 22q11 Deletion syndrome (22qDS) is due to microdeletions of chromosome region 22q11.2, involving multiple genes [Karayiorgou et al., 1995;Bassett and Chow, 1999;Bassett et al., 2001]. 22qDS comprises several genetic syndromes, including velocardiofacial syndrome and DiGeorge syndrome. The most common phenotypic consequences of this deletion are, among others, (1) learning disabilities, (2) palatal anomalies, (3) typical facial features, (4) congenital cardiac defects, and (5) psychiatric disorders. The estimated prevalence of the deletion 22q11.2 is 1/4,000 [du Montcel et al., 1996], which usually occurs as a sporadic mutation, but approximately 10% of cases are inherited from transmitting parents, who often have a less severe phenotype [Demczuk and Aurias, 1995].

Main characteristics of dermatoglypics associated with schizophrenia and its clinical subtypes

“…Also, it was reported that total finger ridge count was reduced in patients with schizophrenia [ 13 , 19 ]. Moreover, value of “atd” angle is observed in higher as compared in general population [ 20 ].…”

The presentation of dermatoglyphic abnormalities in schizophrenia: A meta-analytic review

“…Evidence indicating a link between chromosomal anomalies and alterations in dermatoglyphic and palmar flexion creases suggests genetic influences on the formation of DAs as well (Reed, 1981). Deviant ATD angles have been associated with chromosomal syndromes; namely, in 22q Deletion Syndrome patients, those with mental retardation had greater ATD angles than those with psychotic symptoms, who both had greater angles than healthy controls (Martín et al, 2004). More specifically pertaining to schizophrenia, a family study of people with a schizophrenia spectrum disorder and their first-degree relatives found associations between both genetically-influenced ectodermal derivate abnormalities (e.g., ridge dissociation, abnormal palmar flexion creases) and environmentally-influenced abnormalities such as total a-b ridge count and schizophrenia vulnerability (Fatjó-Vilas et al, 2008).…”

Dermatoglyphics as a possible morphological biomarker in myopia: analysis of finger ridge counts and fluctuating asymmetry

“…Besides, due to their polygenic determination, genes underlying certain disorder may, by pleiotropy, affect dermatoglyphic parameters [12]. This makes them, along with lifetime permanence and the fact that forces that channel ridge differentiation must be operating prior the 19 th week of gestation, a sensitive indicator of intrauterine disturbances associated with chromosomal/gene abnormalities, environmental stress, or a combination of these [28]. Altered dermatoglyphic configuration has been proven in numerous multifactorial or chromosomal disorders [22,28,35].…”