De Novo 1.77-Mb Microdeletion of 10q22.2q22.3 in a Girl With Developmental Delay, Speech Delay, Congenital Cleft Palate, and Bilateral Hearing Impairment.

Interstitial deletions of chromosome band 10q22.1q22.3 are rare. We here report a 2.5-year-old female patient with developmental delay, speech delay, congenital cleft palate, and bilateral hearing impairment. The girl's karyotype was normal. Chromosome microarray analysis (CMA) revealed a 1.77-Mb de novo interstitial deletion in 10q22.2q22.3. The deletion harbors 9 genes, including KAT6B, DUPD1, DUSP13, SAMD8, VDAC2, COMTD1, ZNF503, NCRNA00245, and C10orf11. This is the first patient with a deletion of the smallest size in 10q22.2q22.3 as detected using single nucleotide polymorphism (SNP) arrays. Comparisons with patients with overlapping deletions and in neighboring regions demonstrate the clinical impact of each deletion and in the context of other deletions within the 10q22q23 region. Additionally, KAT6B and C10orf11 could represent disease-associated genes that contribute to developmental delay, speech and language delay, and congenital cleft palate.

Application of high resolution SNP arrays in patients with congenital oral clefts in south China.

Chromosome microarray analysis (CMA) has proven to be a powerful tool in postnatal patients with intellectual disabilities. However, the diagnostic capability of CMA in patients with congenital oral clefts remain mysterious. Here, we present our clinical experience in implementing whole-genome high-resolution SNP arrays to investigate 33 patients with syndromic and nonsyndromic oral clefts in whom standard karyotyping analyses showed normal karyotypes. We aim to identify the genomic aetiology and candidate genes in patients with congenital oral clefts. CMA revealed copy number variants (CNVs) in every patient, which ranged from 2 to 9 per sample. The size of detected CNVs varied from 100 to 3.2 Mb. In 33 patients, we identified six clinically significant CNVs. The incidence of clinically significant CNVs was 18.2% (6/33). Three of these six CNVs were detected in patients with nonsyndromic clefts, including one who presented with isolated cleft lip with cleft palate (CLP) and two with cleft palate only (CPO). The remaining three CNVs were detected in patients with syndromic clefts. However, no CNV was detected in patients with cleft lip only (CLO). The six clinically significant CNVs were as follows: 8p23.1 microduplication (198 kb); 10q22.2-q22.3 microdeletion (1766 kb); 18q12.3 microduplication (638 kb); 20p12.1 microdeletion (184 kb); 6q26 microdeletion (389 kb); and 22q11.21-q11.23 microdeletion (3163 kb). In addition, two novel candidate genes for oral clefts, KAT6B and MACROD2, were putatively identified. We also found a CNV of unknown clinical significance with a detection rate of 3.0% (1/33). Our results further support the notion that CNVs significantly contributed to the genetic aetiology of oral clefts and emphasize the efficacy of whole-genome high-resolution SNP arrays to detect novel candidate genes in patients with syndromic and nonsyndromic clefts.

Ancient DNA reveals that the genetic structure of the northern Han Chinese was shaped prior to 3,000 years ago.

The Han Chinese are the largest ethnic group in the world, and their origins, development, and expansion are complex. Many genetic studies have shown that Han Chinese can be divided into two distinct groups: northern Han Chinese and southern Han Chinese. The genetic history of the southern Han Chinese has been well studied. However, the genetic history of the northern Han Chinese is still obscure. In order to gain insight into the genetic history of the northern Han Chinese, 89 human remains were sampled from the Hengbei site which is located in the Central Plain and dates back to a key transitional period during the rise of the Han Chinese (approximately 3,000 years ago). We used 64 authentic mtDNA data obtained in this study, 27 Y chromosome SNP data profiles from previously studied Hengbei samples, and genetic datasets of the current Chinese populations and two ancient northern Chinese populations to analyze the relationship between the ancient people of Hengbei and present-day northern Han Chinese. We used a wide range of population genetic analyses, including principal component analyses, shared mtDNA haplotype analyses, and geographic mapping of maternal genetic distances. The results show that the ancient people of Hengbei bore a strong genetic resemblance to present-day northern Han Chinese and were genetically distinct from other present-day Chinese populations and two ancient populations. These findings suggest that the genetic structure of northern Han Chinese was already shaped 3,000 years ago in the Central Plain area.

Ancient DNA evidence reveals that the Y chromosome haplogroup Q1a1 admixed into the Han Chinese 3,000 years ago.

OBJECTIVES: Y chromosome haplogroup Q1a1 is found almost only in Han Chinese populations. However, it has not been found in ancient Han Chinese samples until now. Thus, the origin of haplogroup Q1a1 in Han Chinese is still obscure. This study attempts to provide answer to this question, and to uncover the origin and paternal genetic structure of the ancestors of the Han Chinese. METHODS: Eighty-nine ancient human remains that were excavated from the presumed geographic source of the Han Chinese and dated to approximately 3,000 years ago were treated by the amelogenin gene polymerase chain reaction test, to determine their sex. Then, Y chromosome single nucleotide polymorphisms were subsequently analyzed from the samples detected as male. RESULTS: Samples from 27 individuals were successfully amplified. Their haplotypes could be attributed to haplogroups N, O*, O2a, O3a, and Q1a1. Analyses showed that the assigned haplogroup of each sample is correlated to the suspected social status and observed burial custom associated with the sample. CONCLUSIONS: The origins of the observed haplotypes and their distribution in present day Han Chinese and in the samples suggest that haplogroup Q1a1 was probably introduced into the Han Chinese population approximately 3,000 years ago.