De novo ring chromosome 6 in a child with multiple congenital anomalies.
Ring chromosome 6, especially if it is de novo, is a rare occurrence. The phenotype of patients with ring chromosome 6 can be highly variable ranging from almost normal to severe malformations and mental retardation. The size and structure of the ring chromosome as well as the level of mosaicism are important factors in determining the clinical phenotype. Here we report an eight month-old child, a product of a non consanguineous marriage, who presented with developmental retardation, hypertelorism, microcephaly, flat occiput, broad nasal bridge, large ears, micrognathia, wide spaced nipples, protruding umbilicus, short stubby fingers, clinodactyly, single palmar crease, short neck with no obvious webbing, and congenital heart defect. Conventional karyotyping and Whole Chromosome Paint of the peripheral leukocytes showed 46,XY,r(6)(p25q27) karyotype with plausible breakpoints at p25 and q27 end. Conventional karyotyping of both parents showed normal karyotype. To the best of our knowledge, this is the first report of a Malay individual with ring chromosome 6, and this report adds to the collective knowledge of this rare chromosome abnormality.
Human Genetics Unit, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Lot 29, Taman Bertam Indah, Kepala Batas, Penang, Malaysia.
Hadi Ahmad
HA
Ahzad
Siti Fatimah
SF
Ramli
Tan May
TM
Loong
Iman
I
Salahshourifar
Bin Alwi
BA
Zilfalil
Narazah Mohd
NM
Yusoff
D000015:Abnormalities, Multiple / Q000235:genetics*; D025063:Chromosome Disorders / Q000175:diagnosis / Q000235:genetics; D020223:Chromosome Painting; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics; D006801:Humans; D007223:Infant; D007621:Karyotyping; D008297:Male; D010641:Phenotype; D012303:Ring Chromosomes