A Novel Locus of Ectodermal Dysplasia Maps to Chromosome 10q24.32–q25.1

Abstract

Ectodermal dysplasia (ED) represents a heterogeneous group of genetic disorders characterized by the absence or deformity in two or more of the ectodermal appendages. We have studied an autosomal recessive form of ED in 13 individuals over six generations from an inbred Pakistani family. The clinical features of the affected individuals include highly dystrophic nails and thin hair on scalp, fine eyebrows and eyelashes, and thin body hair. Genome-wide linkage analysis of 390 microsatellite markers mapped the ED gene to the 3.92 cM interval flanked by markers D10S1710 and D10S1741 on chromosome 10q24.32-q25.1. Multipoint linkage analysis generated a maximum logarithm of odds ratio score of 4.79 in the interval D10S1239-D10S1264, which corresponds to 6.35 Mb.

A novel mutation in homeobox DNA binding domain of HOXC13 gene underlies pure hair and nail ectodermal dysplasia (ECTD9) in a Pakistani family

“…Based on OMIM classification, there are five autosomal recessive pure hair and nail ectodermal dysplasia types have been reported. These includes ectodermal dysplasia hair and nail type 4 (ECTD4; MIM 602032) lying on chromosome 12q13.13 with mutations in KRT85 gene [3], ectodermal dysplasia hair and nail type 5 (ECTD5; MIM 614927) located on chromosome 10q24.32-q25.1 [4], ectodermal dysplasia hair and nail type 6 (ECTD6; MIM 614928) with chromosomal address 17p12-q21.2 [5], ectodermal dysplasia hair and nail type 7 (ECTD7; MM 614929) lying on chromosome 12q13.13 with mutation in KRT74 gene [6] and ectodermal dysplasia hair and nail type 9 (ECTD9; MIM 614931) harboring HOXC13 gene on chromosome 12q13.13 [7–9]. …”

A Novel Homozygous Missense Mutation in HOXC13 Leads to Autosomal Recessive Pure Hair and Nail Ectodermal Dysplasia

“…Pure hair and nail ectodermal dysplasia (PHNED), also known as ectodermal dysplasia of the hair and nail type, is a rare subtype in which hypotrichosis and nail dystrophy are present but other ectodermal structures, including the teeth and sweat glands, and nonectodermal‐derived structures remain unaffected . Autosomal dominant and autosomal recessive forms of PHNED have been described. There is considerable phenotypic variation, with severity ranging from mild hypotrichosis to complete absence of all vellus, lanugo, and terminal hairs.…”

“…PHNED has significant genetic heterogeneity. The autosomal recessive form of this disorder (PHNED‐AR) has been mapped to several loci: 17p12‐q21.2 , 10q24.32‐q25.1 , 12p11.1‐q21.1 , and 12p11.1‐q14.3 . In 2006, Naeem et al were the first to link a specific gene to PHNED‐AR when they found a homozygous missense mutation in KRT85 (Online Mendelian Inheritance in Man [OMIM] 602767) in affected members of a consanguineous Pakistani family.…”

Ectodermal dysplasia of hair and nail type: mapping of a novel locus to chromosome 17p12-q21.2

“…Both the child's parents were clinically unaffected, suggesting either autosomal recessive inheritance or a de novo autosomal dominant mutation. An autosomal recessive form of pure hair and nail ED was described in a Pakistani family of 13 affected individuals 6 . The patients had thin scalp and body hair and fine eyebrows and eyelashes.…”

“…An autosomal recessive form of pure hair and nail ED was described in a Pakistani family of 13 affected individuals. 6 The patients had thin scalp and body hair and fine eyebrows and eyelashes. Nail dystrophy was present in all digits.…”