Radial Count Research Articles

Dermatoglyphic analysis of autistic Basque children

We have analyzed the digital and palmar dermatoglyphics in a sample of autistic children from the Basque Country. The results have been compared with those from a control sample having the same characteristics relative to the ethnic region. We found significant differences between the digital dermatoglyphics of autistic boys and control boys. Autistic children have a higher frequency of transitional radial loops and a lower frequency of dicentric whorls; also the total finger ridge count (TFRC) and radial count are lower in autistic individuals. There were no significant differences in the girls. In palmar dermatoglyphics, autistic girls have a lower frequency of radial loops in the hypothenar area, and the value of the "atd" angle is higher than in control girls. These differences were significant. The a-b interdigital ridge count is significantly lower in autistic boys. Autistic children of both sexes have a higher frequency of aberrant palmar creases. The results obtained in the present study do not contradict the hypothesis that genetic factors may be important in autism of unknown cause.

Diminished radial count is found only postnatally in Down's syndrome.

Acinar complexity was assessed using the radial count in 23 patients with Down's syndrome. Late intrauterine growth of the lung is not impaired, and acinar complexity is normal. Thereafter, decreased acinar complexity occurs and is grossly and microscopically apparent by 4 months of age. The gross appearance is characteristic, consisting of a diffuse and uniform porosity of the cut surface of the lung. Microscopically, this appearance is due to the presence of dilated alveoli and alveolar ducts. Children and adults with Down's syndrome have a significantly reduced number of alveoli, which are enlarged. In the majority of cases, the alveoli have a double capillary network that has not been described in any other lung condition. No correlation could be established between the radial count and the presence or absence of double capillary network, hypertensive pulmonary vascular disease, or congenital heart disease. The unique appearance of the lung in Down's syndrome results from failure of the lung to develop properly in the postnatal period, presumably genetically determined.

Hypoplasia and immaturity of the terminal lung unit (acinus) in congenital diaphragmatic hernia.

We assessed the maturity of the lungs and the radial count in 10 infants with congenital diaphragmatic hernia who died in the immediate perinatal period. The lungs were all immature, with a histologic appearance of less than stated gestational age. The ipsilateral lungs were less mature in appearance than were the contralateral ones. The radial count, an assessment of acinar complexity, was reduced in all cases, and once again the ipsilateral lung was more affected. We present evidence that, in 4 of 6 lungs, volumes were more reduced than predicted from the radial count, and this may be due to loss of (airway) units. We have discussed the controversy about the appearance of the acinus in diaphragmatic hernia and present reasons to explain this. Hyaline membrane disease often occurs in diaphragmatic hernia, even at full term. Intra-alveolar hemorrhage is a common complication of diaphragmatic hernia.

Digital dermatoglyphics of the Faroe Islanders.

Finger dermatoglyphics of 446 male and 463 female Faroe Islanders are described. According to birthplace information for their grandparents the individuals sampled are considered to be representative of all regions of the Faroes. Pattern frequencies are given for individual digits and the tables contain mean radial, ulnar, and unilateral maximal ridge counts. Overall frequencies of patterns and mean total ridge counts in both sexes are compared with other populations in northwestern Europe, several of which have had close historical connections with the Faroes. The Faroese have exceptionally high frequencies of arch and ulnar loop patterns, making their mean pattern intensity index values among the lowest in Europe. Low mean total ridge counts are also characteristic of this population. Icelanders show closer dermatoglyphic resemblance to the Faroese than any other European populations. Low mean total ridge counts among Shetland and Orkney Islanders are noteworthy, and it is possible that the resemblance between these North Atlantic island populations is due to common ancestry arising from Viking settlement during the 8th and 9th centuries. The operation of random genetic drift on the gene pool of the Faroe Islanders is another factor to be considered when assessing their biological affinities.

The radial alveolar count method of Emery and Mithal: a reappraisal 2--intrauterine and early postnatal lung growth.

The radial count method of Emery and Mithal was applied to the lungs of 37 infants of gestational age 19-42 weeks. The method could be used satisfactorily to evaluate airspace-containing lungs, whether alveolated or non-alveolated (saccule-containing). There was a progressive increase in complexity of terminal lung units throughout gestation, and a smooth transition was effected at 1 month of age between the radial counts of the intrauterine cohort and those of a separate group used to study postnatal lung growth. In the intrauterine and early postnatal group radial count results correlated very closely with the total gestational age (gestational age plus survival time after birth) of the child (r = +0.93). Prior inflation of the lungs affected the radial counts of alveolated lungs much more than those of saccule-containing lungs, so that results correlated most closely with those of Emery and Mithal in the period up to 34 weeks' gestation. Radial count estimation correlated better with total gestational age, crown-rump length, body weight, and fixed lung volume than did any other morphometric parameter assessed. The radial count method provides a reliable index of lung growth in intrauterine and early postnatal development.

The radial alveolar count method of Emery and Mithal: a reappraisal 1--postnatal lung growth.

The radial alveolar count method of Emery and Mithal has been re-evaluated on 76 normal postnatal lungs. Results of reproducibility assessments suggest that each observer should establish normal control values when beginning with the method, and should subsequently use control cases to maintain strict reproducibility. The use of 10 fields per case was found to be inadequate to obtain satisfactory reproducibility, even for a single observer. Prior inflation of the lungs significantly increased the radial counts, and this factor may help to explain the large discrepancy between the results of this study and that of Emery and Mithal. The radial counts correlated well with the chronological age of the child (r = +0.76; p less than 0.001). Alveolarization of the acinus occurs primarily between birth and 2 years; significant but slower growth is seen up to 8 years, after which the results plateau, suggesting that alveolarization is complete. The radial count method appears to provide a relatively simple and reasonably satisfactory assessment of alveolar development, as originally proposed by Emery and Mithal.

Fingerprint pattern factors.

Factor analysis was employed using the ulnar ridge count, radial ridge count, ridge count (the larger of the radial or ulnar count as generally used for calculating total ridge count), and pattern type for each finger in 720 twins. Pattern type and ulnar count displayed parallel factor loadings while loadings for radial and ridge count also paralleled each other. This relationship did not hold for the index finger, indicating the importance of pattern direction and greater pattern diversity for this digit. Total ridge count was most closely associated with a factor of ring and little finger radial and ridge count and only secondarily with an index finger factor. When radial and ulnar counts were deleted to make comparisons with earlier studies, the result was factors having groupings of variables identical with previous reports. It appears that factor analysis results in consistent extraction of identical or very similar factors from different populations, and the use of radial and ulnar counts adds more information than when only the larger of the two counts is considered.

A non-linear function for maximizing the parent-offspring regression

In the quantitative inheritance of finger-ridge counts, it is conventional to take the largest of the ulnar and radial ridgecounts as a measure of the pattern size. In the case of a loop, there is but one measurement, a radial count on an ulnar loop, and an ulnar count on a radial loop. In a whorl there are (usually) two counts, and it is in this instance when the convention is used. In the case of an arch, both ulnar and radial counts are zero.